In this case we examine whether an employee has the right to seek out his employer and voluntarily quit his job on terms agreeable to both him and his employer, or whether that basic right must be bargained for on his behalf by his union. The Soo Line Railroad Company (Soo Line) appeals from a decision of the United States District Court for the District of Minnesota, permanently enjoining the Soo Line from entering into voluntary separation agreements with individual members of the International Association of Machinists and Aerospace Workers, District Lodge No. 19 (IAM or Union).
The Soo Line contends on appeal that the district court did not have subject matter jurisdiction over the disagreement between the Soo Line and IAM because (1) the disagreement between them is not a dispute, as that term is used in the Railway Labor Act, 45 U.S.C. §§ 151-188 (RLA); (2) even if the disagreement is a dispute within the ambit of the RLA, it is a minor dispute subject to resolution by the National Railroad Adjustment Board; and (3) the pertinent agreements between the Soo Line and IAM require arbitration of any dispute arising out of their interpretation or application, and this is such a dispute.
We discuss these sequentially. Section 2 of the Railway Labor Act, 45 U.S.C. § 151a, sets out the disputes to which it applies as “all disputes concerning rates of pay, rules, or working conditions” and “all disputes growing out of grievances or out of the interpretation or application of agreements covering rates of pay, rules, or working conditions.” As we explain more fully in Section 11(B), numerous courts have assumed the presence of a labor dispute in situations similar to the one at issue.1 We therefore base our decision on the Soo Line’s second and third arguments. Accordingly, we conclude that the district court erroneously asserted equitable jurisdiction in this case, and we reverse and remand for arbitration.2
1. BACKGROUND.
This case has its genesis on February 19, 1985, when the Soo Line acquired the core rail assets of the Chicago, Milwaukee, St. Paul and Pacific Railroad Company (Milwaukee) from its trustee in bankruptcy. Two statutory regimes governed the Soo Line’s acquisition of Milwaukee (Acquisition): the Milwaukee Railroad Restructuring Act, 45 U.S.C. §§ 901-922 (the Restructuring Act), and the Interstate Commerce Act, 49 U.S.C. § 10101 et seq. (ICA).
A. The Restructuring Act.
The Restructuring Act was passed as an emergency measure to restructure the financially ailing Milwaukee, in order to avoid the potential unemployment and economic damage that would result if the Milwaukee were to cease operating. 45 U.S.C. § 901(b). The Restructuring Act primarily sets out procedures through which courts, the Secretary of Transportation, and the Interstate Commerce Commission (ICC) may supervise transactions pertaining to the Milwaukee, such as sales, transfers, *371abandonments, and conversion plans. 45 U.S.C. §§ 903-905, 915. The Restructuring Act also sets out a variety of protective measures for Milwaukee employees, 45 U.S.C. §§ 907-914.
The Restructuring Act required the Soo Line, as a condition of the Acquisition of Milwaukee, to provide protections for potentially affected employees. Section 904(b)(1) of the Restructuring Act set out the level of protection required, and authorized the federal district court supervising the Acquisition (reorganization court) to decide for itself what specific labor protective conditions should be imposed. Section 904(b)(1) provides: “In authorizing any such sale or transfer, the court shall provide a fair arrangement at least as protective of the interest of employees as that required under section 11347 of title 49 of the United States Code.” (Section 11347 of the ICA.)3 This mandate brings us to the second of the two statutes governing the transaction, the ICA.
B. The ICA Protective Agreement.
As this court recently stated in Burlington Northern Railroad Co. v. United Transportation Union, 848 F.2d 856, 859-60 (1988), the goal of the ICA is to make commerce flow smoothly, to the benefit of both American industry and consumers. The ICA seeks to ensure fair shipping rates, safety and efficiency in transportation, and to preserve the viability of various modes of transportation. See 49 U.S.C. §§ 10101, 10101a.
The ICA generally requires that before a railroad acquires an additional line, the rail carriers involved in the transaction must obtain the approval of the ICC. 49 U.S.C. § 10901. In furtherance of the ICA’s goal of preventing labor strife by “encourag[ing] fair wages and safe and suitable working conditions in the railroad industry,” 49 U.S.C. § 10101a(12), the ICC, before approving a particular transaction, has generally required the imposition of plans to compensate workers displaced by the transaction. See 49 U.S.C. § 11347. These plans are called labor protective provisions or agreements. Under the authority granted by the ICA, the ICC has developed standard labor protective provisions for particular types of transactions. When the transaction involves the sale of a rail line, such as here, the ICC imposes the New York Dock conditions upon the parties. See New York Dock Railway—Control—Brooklyn E.D. Terminal, 360 I.C.C. 60 (1979), aff'd, 609 F.2d 83 (2d Cir.1979).
The New York Dock conditions provide essentially that any employee furloughed as a result of a merger or similar transaction must be paid, generally for six years, the equivalent of the wage earned at the time of the adverse action, unless he or she chooses instead to take a one-time payment of up to one year’s pay (valued at approximately $38,000 per employee in this case); that issues pertaining to seniority and contract rights between the employees of the two merged railroads must be resolved by an implementing agreement with the consolidated railroad’s unions; that existing collective bargaining agreements must be preserved; and that mandatory and binding arbitration be used to resolve “any dispute or controversy with respect to the interpretation, application or enforcement of any provision” of the New York Dock conditions.4
*372The Soo Line informed both the ICC and the reorganization court that several hundred employees would lose their jobs as a result of the Acquisition. See Matter of Chicago, Milwaukee, St. Paul and Pacific Railroad Co., 799 F.2d 317, 328-29 (7th Cir.1986), cert. denied, — U.S. -, 107 S.Ct. 2460, 95 L.Ed.2d 869 (1987). The ICC recommended that the New York Dock conditions be imposed upon the Acquisition, and the reorganization court, except for making minor changes,5 applied the New York Dock conditions.
Accordingly, on September 10, 1985, the Soo Line entered into an employee protective agreement (Protective Agreement) with Milwaukee and IAM. The Protective Agreement, which incorporated the New York Dock conditions in conformity with the reorganization court’s order, was meant to provide standard labor protective provisions pursuant to section 11347 of the ICA and the Restructuring Act. As described in its preamble, the purpose of the Protective Agreement was:
to provide * * * for fair and equitable arrangements to protect the interests of Employees adversely affected by the Acquisition; and to provide for expedited changes in services, facilities, operations, seniority and existing collective bargaining agreements to enable the expanded railroad system created by the Acquisition to be operated in the most efficient manner, as one completely integrated railroad.
C. The RLA Collective Bargaining Agreement.
Before the execution of the Protective Agreement, as a result of negotiations entirely unrelated to the Acquisition, the Soo Line and IAM entered into a collective bargaining agreement (CBA) on March 1, 1985. The CBA was negotiated in accordance with the provisions of the RLA, which seeks among its aims to secure the “complete independence” of railroads and their employees in matters of self-organization to carry out the purposes of the RLA. See 45 U.S.C. § 151a. The CBA set out rules concerning working hours and conditions, layoffs, promotions, seniority, grievances and employee discipline. The CBA made no explicit mention of an employee’s right of voluntary resignation.
D. The Voluntary Separation Plan.
Post-Acquisition, in December 1985, the Soo Line decided to reduce the number of employees on its payroll. It offered voluntary separation pay plans to certain employees represented by unions other than IAM. Under these plans, employees who voluntarily resigned would receive $15,000 cash in a lump-sum severance payment and, if they were age sixty or older, would have their health benefits continued until they were sixty-five. To take advantage of the plan, each employee was required to:
Release all rights under labor protective conditions, including but not limited to, statutory, contract, or agreement labor protection and those conditions commonly referred to as Appendix B. * * * [RJesign and relinquish all rights of or claims to employment with the Soo Line Railroad * * * and release and discharge said railroad company, * * * from any and all claims of whatsoever kind and *373nature growing out of or in connection with said employment.
Soo Line Railroad Voluntary Separation Pay Plan at p. 3.
Many employees accepted the separation plan and terminated their services with the Soo Line. For example, on December 11, 1985, the Soo Line offered a voluntary separation pay plan to certain employees represented by the United Transportation Union (UTU). There were no negotiations with the UTU, and eighty-one UTU employees voluntarily participated in the plan. Likewise, on January 31,1986, the Soo Line offered to employees classified as “engine-men” represented by the UTU and the Brotherhood of Locomotive Engineers (BLE) a similar voluntary separation plan. Again, there were no negotiations with either of these unions and fifty-six BLE and UTU enginemen accepted the plan and terminated their services with the Soo Line.
In addition, numerous other Soo Line employees from ten different “old-line” labor unions (other than UTU and BLE) voluntarily requested and were granted separation pay plans. The Soo Line did not negotiate with either the employees or their unions regarding the plans. Neither the UTU, the BLE, nor any of the ten other unions even sought to negotiate with the Soo Line as to these voluntary plans, and at no time did these unions protest that offering the plans constituted a major dispute under the RLA. In all, nearly 400 union-represented employees accepted voluntary separation plans.
IAM learned of the program and questioned the Soo Line with respect to the applicability of the program to machinists. The Soo Line said it was not making such a plan available to the machinists. Thereafter, eight machinists, all over sixty years of age and with top seniority, contacted the Soo Line asking to participate in a similar plan. Of the eight, those who met certain additional qualifications, see 45 U.S.C. § 231a(a), were also eligible for retirement annuities under the Railroad Retirement Act of 1974, 45 U.S.C. § 231 et seq. The eight machinists’ requests were honored and, after signing the necessary releases, their services with the Soo Line were terminated. Each received a separation allowance of $15,000 and became eligible to continue to receive certain health benefits until age sixty-five.
E. The District Court Injunction.
When IAM learned that the separation plan was being offered to some of its members, it objected. In response to this objection, the Soo Line agreed to meet with IAM voluntarily and informally, in an effort to alleviate its concerns.6 These discussions were unsuccessful. The Soo Line thereafter announced its intention to solicit other machinists’ resignations pursuant to a voluntary separation plan (the Individual Plan), containing essentially the same terms as the agreements signed by other Soo Line employees. IAM then filed this action seeking to restrain the Soo Line from entering into the Individual Plan with individual machinists. IAM argued that the Individual Plan contravened the New York Dock conditions because its effect was to relieve the Soo Line of its obligations under those conditions. IAM contended that the eight senior machinists who voluntarily resigned would reduce by eight the number of employees who would have been furloughed as a result of the merger and thus would have been entitled to benefits under the New York Dock conditions. IAM claimed in effect that the early retirement program was an attempt to substitute a uniform lump-sum payment of $15,000 for payment for six years of service (or alternatively, $38,000) under the Protective Agreement.
*374The matter was submitted to the district court on affidavits, exhibits, and abbreviated oral testimony. The parties stipulated that the hearing on the preliminary injunction could be considered the hearing for a permanent injunction. The district court first looked to section 6 of the RLA and reasoned that it:
establishes a comprehensive series of bargaining procedures, complete with detailed timetables and provisions for notice, to be followed by employers and bargaining representatives in effecting changes in rates of pay, rules, and working conditions. 45 U.S.C. 156. When employers wish to make changes in any regulated areas, the statute mandates written notice of the desired modification, after which conferences between management and labor take place, with the optional assistance of the National Mediation Board.
District Court Order at 3-4.
The district court then reviewed the cases which have defined the concededly hazy continuum between major and minor disputes and found that the dispute between the parties was major. It stated:
[T]he Court is not called upon to review the status of either labor or management at the interstices of an agreement. Instead, the case presents fundamental issues of whether or not a person may even be an employee or a member of a union. We are not defining an inter-employment relationship, but the fundamental nature of the employment relationship itself.
Both parties agree that there is no provision in the existing agreements between the Union and Soo Line allowing solicitation of individual union members or for individual lump-sum separation agreements. Under the Elgin definition and the decisions of the other courts which have faced the jurisdictional issue in the present context, this dispute is major, and this Court therefore has jurisdiction over it.
Id. at 6.
The court went on to hold that individual agreements such as the Individual Plan proposed by the Soo Line were impermissible, and enjoined the Soo Line from entering into the Individual Plan with employees represented by the Union until such time as the Soo Line complied with the notice, bargaining and mediation procedures of section 6 of the RLA, which have been called “almost interminable.” See Brotherhood of Maintenance of Way Employees v. Chicago and North Western Transportation Co., 827 F.2d 330, 333 (8th Cir.1987).
II. DISCUSSION.
In reviewing the district court’s grant of a permanent injunction in this case, we note that appellate review of either a grant or denial of injunctive relief is confined to the familiar determination of whether the trial court abused its discretion. See Olin Water Services v. Midland Research Laboratories, Inc., 774 F.2d 303, 307 (8th Cir.1985). Abuse of discretion occurs if the district court rests its conclusion on clearly erroneous factual findings or if its decision relies on erroneous legal conclusions. Brotherhood of Locomotive Engineers v. Burlington Northern Railroad Co., 838 F.2d 1102, 1104 (9th Cir.1988). Whether a matter is a dispute under the RLA, and if so, whether it is a major dispute or a minor dispute, are both questions of law which we review de novo. See Brotherhood of Locomotive Engineers v. Burlington Northern Railroad Co., 838 F.2d 1087, 1089 (9th Cir.1988).
We are also well aware that our inquiry as to the probity of an injunction is limited to those issues directly related to the injunction, for “[a]n injunction does not settle a dispute — it simply disables one of the parties,” Burlington Northern Railroad Co. v. Brotherhood of Maintenance of Way Employes, — U.S. -, 107 S.Ct. 1841, 1854, 95 L.Ed.2d 381 (1987). With these parameters in mind, we proceed to examine the three issues in this case.
A. Existence of a Dispute.
We first examine the district court’s conclusion that the disagreement at issue in this case is a dispute under the RLA. Section 2 of the RLA, 45 U.S.C. § 151a, pro*375vides that one of the purposes of the RLA is “to provide for the prompt and orderly settlement of all disputes concerning rates of pay, rules, or working conditions.”
The Soo Line argues that no “dispute,” as that term is contemplated by the RLA, exists here; rather, the Soo Line characterizes the situation as one involving a matter of voluntary choice, personal to each employee. The Soo Line maintains that this case does not concern “rates of pay, rules, or working conditions,” nor is an employee’s right to resign derived from, dependent upon, or governed by a collective bargaining agreement. Simply put, the Soo Line argues that the RLA does not govern an employee’s right to voluntarily separate from employment under terms advantageous to him. The district court concluded, however, that the Soo Line’s offer of the Individual Plan to employees violated the RLA.7 We disagree. Our examination reveals that the statutory language and case law allow the Soo Line to offer employees the Individual Plan in full compliance with the RLA.
As a starting point, the RLA itself appears to recognize an employee’s right to terminate his employment relationship on terms he finds acceptable:
Nothing in this chapter shall be construed to require an individual employee to render labor or service without his consent, nor shall anything in this chapter be construed to make the quitting of his labor or service by an individual employee an illegal act; nor shall any court issue any process to compel the performance by an individual employee of such labor or service, without his consent.
45 U.S.C. § 159 Eighth.
The Supreme Court has also spoken on this issue. The Court has stated, simply, that certain individual employment contracts may exist side-by-side with a collective bargaining agreement. See J.I. Case Co. v. National Labor Relations Board, 321 U.S. 332, 339, 64 S.Ct. 576, 581, 88 L.Ed. 762 (1944); Order of Railroad Telegraphers v. Railway Express Agency, Inc., 321 U.S. 342, 347, 64 S.Ct. 582, 585, 88 L.Ed. 788 (1944); Caterpillar Inc. v. Williams, — U.S. -, 107 S.Ct. 2425, 2431-32, 96 L.Ed.2d 318 (1987). The principles set out in J.I. Case and its progeny are equally applicable to employees covered by the RLA and the National Labor Relations Act. Order of Railroad Telegraphers, 321 U.S. at 347, 64 S.Ct. at 585.
At least one circuit court, the National Mediation Board, and the National Railroad Adjustment Board have condoned voluntary quits. See Antonioli v. Lehigh Coal and Navigation Co., 451 F.2d 1171, 1175 (3d Cir.1971), cert. denied, 406 U.S. 906, 92 S.Ct. 1608, 31 L.Ed.2d 816 (1972); Brotherhood of Railway Carmen of the United States and Canada v. Illinois Gulf Central Railroad, National Mediation Board Case No. 6, Public Law Board No. 2603 (1980); System Federation No. 69, Railway Employes’ Dep’t v. Florida East Coast Railway Co., National Railroad Adjustment Board Award No. 4733 (2d Div.1965), slip op. at 30; System Federation No. 2, Railway Employes’ Dep’t v. Missouri Pacific Railroad Co., National Railroad Adjustment Board Award No. 1579 (2d Div.1952), slip op. at 4.
In sum, there is strong support for the Soo Line’s position that no dispute under the RLA exists here. We are mindful, however, of the substantial case law, see infra, that has found the existence of a dispute under similar circumstances. We are also aware of the strong presumption of arbitrability in these types of cases, see supra Ozark Air Lines, 744 F.2d at 1350. Thus, we assume without deciding that the district court was correct in its conclusion that this case implicates a “dispute” under the RLA.
*376B. Major-Minor Dispute.
Proceeding on the assumption that this case does indeed present a dispute, we think the conclusion is inescapable that the dispute is minor.
The Supreme Court set out the difference between major and minor disputes under the RLA in Elgin, Joliet & Eastern Railway Co. v. Burley, 325 U.S. 711, 65 S.Ct. 1282, 89 L.Ed. 1886 (1945):
[I]t is clear from the [Railway Labor] Act itself, from the history of railway labor disputes and from the legislative history of the various statutes which have dealt with them, that Congress has drawn major lines of difference between the two classes of controversy.
The first [“major” disputes] relates to disputes over the formation of collective agreements or efforts to secure them. They arise where there is no such agreement or where it is sought to change the terms of one, and therefore the issue is not whether an existing agreement controls the controversy. They look to the acquisition of rights for the future, not to assertion of rights claimed to have vested in the past.
The second [“minor” dispute] class, however, contemplates the existence of a collective agreement already concluded or, at any rate, a situation in which no effort is made to bring about a formal change in terms or to create a new one. The dispute relates either to the meaning or proper application of a particular provision with reference to a specific situation or to an omitted case.
Elgin, 325 U.S. at 722-23, 65 S.Ct. at 1289. (Footnotes omitted; emphasis added.) The Supreme Court went on to explain that major disputes involve “large issues about which strikes ordinarily arise” while minor disputes affect smaller differences which “arise incidentally in the course of an employment” and are “of a detailed or individual quality.” Id. at 723-24, 65 S.Ct. at 1290.
Section 3 of the RLA commits minor disputes over the “interpretation or application” of existing agreements and practices to the exclusive jurisdiction of Adjustment Boards, i.e., to “compulsory arbitration.” 45 U.S.C. § 153 First (i); Brotherhood of Railroad Trainmen v. Chicago River & Indiana Railroad Co., 353 U.S. 30, 39, 77 S.Ct. 635, 640, 1 L.Ed.2d 622 (1957); see Elgin, 325 U.S. at 724, 65 S.Ct. at 1290. While the controversy is pending before the Board, the carrier may apply its reasonable interpretation of the disputed agreement, with limited exceptions not here relevant. Brotherhood of Maintenance of Way Employees v. Burlington Northern Railroad Co., 802 F.2d 1016, 1022 (8th Cir.1986).
In deciding whether a dispute is major or minor, it is not our function to interpret or construe the language of the collectively bargained-for agreements between the parties (the CBA and Protective Agreement); rather, our function is to determine whether this case implicates a question of contract interpretation. International Association of Machinists v. Northwest Airlines, Inc., 843 F.2d 1119, 1122 (1988). If the parties disagree whether the dispute can be resolved by reference to an agreement, the dispute is minor unless the claims of contractual justification are “frivolous” or “obviously insubstantial.” Maine Central Railroad Co. v. United Transportation Union, 787 F.2d 780, 783 (1st Cir.), cert. denied, — U.S. -, 107 S.Ct. 169, 93 L.Ed.2d 107 (1986); Chicago and Northwestern Transportation Co. v. United Transportation Union, 656 F.2d 274, 278-79 (7th Cir.1981). This circuit has framed the test as follows:
This Court has said that a dispute is minor if the agreement is “reasonably susceptible” of the interpretations sought by both the employer and the employees. Other courts have said that a dispute is minor if the employer’s action can be arguably justified under the terms of the existing agreement, or that the dispute is minor unless the employer’s argument that its actions are within the contract is “obviously insubstantial.” These locutions are essentially the same in their result. They illustrate the relatively light burden which the [Soo Line] must bear in showing that its actions are at most minor changes and thus within the status quo.
*377Brotherhood of Maintenance of Way Employees v. Burlington Northern Railroad Co., 802 F.2d 1016, 1022 (8th Cir.1986) (citations omitted); see also United Transportation Union v. Burlington Northern, Inc., 458 F.2d 354, 357 (8th Cir.1972). This rule is a necessary adjunct of the need to protect the arbitrator’s exclusive jurisdiction over minor disputes and supports the additional corollary that “when in doubt, the courts construe disputes as minor.” Brotherhood of Locomotive Engineers v. Atchison, Topeka and Santa Fe Railway Co., 768 F.2d 914, 920 (7th Cir.1985).8 Thus, in this case, if the bargained-for agreements arguably permit the practice, then the Soo Line may proceed unilaterally, subject to arbitration before the National Railroad Adjustment Board. Brotherhood of Maintenance of Way, 802 F.2d at 1021-22.
IAM contends that the disagreement over the Individual Plan is a major dispute. While both parties agree that the CBA does not authorize or prohibit this type of “voluntary quit” plan, IAM argues that the terms of the Individual Plan are in direct conflict with the Protective Agreement. The Soo Line, on the other hand, contends that the Protective Agreement and the Individual Plan may coexist because the Individual Plan is entirely voluntary, results only in an employee’s resignation, and does not unilaterally change the rules, working conditions or rates of pay for employees that choose to remain employed with the Soo Line.9 According to the Soo Line, an employee has the right to terminate his employment at will on any terms he or she can obtain from the employer. The Soo Line also argues that the Individual Plan furthers this right and does not violate or undermine the CBA; therefore, it is a retained “management prerogative,” and thus does not constitute direct dealing with employees in violation of the RLA.10
*378As we have noted, the touchstone of a major-minor dispute is whether a party’s position is frivolous or clearly insubstantial. A number of tribunals have held that the very argument that the Soo Line sets forth here presents a minor dispute.
In Chambers v. Burlington Northern, Inc., 692 F.2d 109 (10th Cir.1982), the court examined a dispute arising out of an employee transfer. The defendant, Burlington Northern (BN), formed in a merger of several railways in 1970, was required by the ICC to enter into a protective agreement, and accordingly executed a “Merger Protection Agreement” (MPA). The MPA and the merger were approved by the ICC.
Plaintiff Chambers was an engineer-fireman who was transferred. He executed a written agreement with BN in which he voluntarily relinquished his seniority in exchange for a lump-sum payment. Chambers, 692 F.2d at 110. When Chambers entered the agreement with BN he was subject to two collective bargaining agreements (CBAs), neither of which had provisions applicable to seniority or allowances on transfer.
Ten months after Chambers had signed his lump-sum agreement with BN, however, BN and the unions made new CBAs which gave a transferred employee both more money on transfer and provided that the transferred employee would retain his prior seniority. Chambers sued, arguing that BN had violated the MPA because his agreement with BN provided him less protection than was contained in the later CBA.
The court stated:
[T]he question of forestalling and changing of obligations requires consideration, interpretation, and application of the MPA, the Union agreement in effect when the individual agreement was made, and the bargaining agreement made ten months after the individual agreement.
Chambers, 692 F.2d at 111. The court went on to hold that the dispute was minor and must be submitted to the exclusive jurisdiction of the National Railroad Adjustment Board, because “[i]n the final analysis, the dispute here relates to the interpretation and application of the MPA and the bargaining agreements.” Id. at 112.
In Clausen v. Burlington Northern, Inc., 106 LRRM 2496 (D.Mont.1980) [available on WESTLAW, 1980 WL 2113], the district court faced an issue similar to that in this case. Clausen was employed by BN as a fireman-engineer. The ICC required the implementation of a merger protective agreement (MPA), when BN was formed. The MPA provided protection for employees transferred by BN, but contained no provision for seniority adjustments on transfer.
Clausen and BN agreed that Clausen would accept a transfer. The agreement provided that Clausen would relinquish his prior seniority and reestablish it in the new location. Thereafter, BN and the Brotherhood of Locomotive Engineers negotiated a new collective bargaining agreement, which contained provisions covering benefits for transferred employees. The benefits in the new agreement exceeded those Clausen had received. Clausen filed suit, alleging that the individual agreement he negotiated with BN violated the RLA and the MPA, which incorporated the new col*379lective bargaining agreement. The court held that the dispute was minor, stating at 106 LRRM 2499-2500:
The fundamental conflict here is whether relevant sections of a Merger Protection Agreement apply to and permit the execution of individual contracts regarding seniority transfers. The plaintiff is attempting to avail himself of certain compensation provisions of the May 28,1975, agreement between B.N. and UTU-E. Plaintiff also seeks restoration of his original seniority status and the difference between lump sum payments under his individual contract and the subsequent B.N.-UTU-E agreement. The plaintiff contends that § 6 of the MPA is violated by the individual contract negotiated with the defendant. * * * Therefore, plaintiff maintains that a collective agreement encompasses the issue in dispute and defendant contends that such agreement does not contemplate the specific controversy involved herein. Thus, the validity of the individual agreement negotiated by the parties necessarily requires interpretation and application of relevant provisions within the Merger Protection Agreement in effect at the time of the letter agreement negotiation. Interpretation and application of collective bargaining agreements within this context have consistently been deferred to the specialized expertise of the National Railway [sic] Adjustment Board.
In International Association of Machinists and Aerospace Workers v. Illinois Central Gulf Railroad Co., 102 Lab. Cas. ¶ 11,345 (S.D.Ill.1984) [available on WESTLAW, 1984 WL 1451], the district court examined a factual dispute similar to the one presented here. Illinois Central made individual agreements with furloughed employees for lump-sum payments in exchange for the individual employee’s resignation, allegedly in violation of both a collective bargaining agreement and merger protective agreement. Illinois Central argued that the merger protective agreement, combined with past practices in which the unions acquiesced, gave Illinois Central the right to make the individual agreements. The union argued that no such past practices existed, and that any individual severance agreements were in derogation of the collective bargaining agreement.
After examining the record, the court held that Illinois Central’s argument that there was a past practice of making individual severance agreements was not frivolous, nor was the union’s argument that there was no such past practice.11 In view of the fact that “a dispute over the interpretation of rights under implied agreements based on past practices is a minor dispute, as long as both parties advance on interpretation that is not frivolous,” Railway Express Agency v. Brotherhood of Railway, Airline and Steamship Clerks, 437 F.2d 388 (5th Cir.), cert. denied, 403 U.S. 919, 91 S.Ct. 2230, 29 L.Ed.2d 696 (1971), the court held the dispute to be minor and subject to mandatory arbitration. More importantly for our purposes, the court went on to state:
Even if there were no past practice of making individual agreements, this matter should still be one subject to arbitration under the Merger Agreement which imposes protective conditions upon [Illinois Central]. The Merger Agreement has an arbitration clause and therefore any interpretation of the agreement is within the jurisdiction of the adjustment board. See Illinois Central Railroad v. Wood, Civil No. 69-107 (E.D.Ill.1970). The severance agreements were made *380with protected employees, arguably in compliance with the Merger Agreement.
Thus the court, completely apart from the past practices argument, based its decision on the fact that the merger agreement had to be interpreted to resolve the dispute, because Illinois Central's actions arguably were in compliance with the Merger Agreement.
The major-minor dispute issue was most recently addressed in Transportation-Communication Employees Union v. Grand Trunk Western Railroad Co., 679 F.Supp. 696 (E.D.Mich.1988). The union contended that management had violated the RLA and various bargained-for agreements, by engaging in direct negotiation with individual employees on the issue of separation agreements without consulting the union. The union sought an injunction prohibiting management from offering the individual separation plans. The court declined to assume jurisdiction, finding the dispute to be minor because “the individual separation agreements arguably are consistent with, and authorized by, the express terms of the * * * Protective Agreement.” At 699. The court also found not frivolous management’s assertion that the union had agreed, through past practice, to the offering of the individual plans. Here as well the Individual Plan arguably is “consistent with, and authorized by,” the Protective Agreement.
These cases stand for the proposition that the Soo Line’s assertion (i.e., that the Individual Plan does not violate the CBA and Protective Agreement) is not frivolous. This is so for the simple reason that the overwhelming majority of courts to consider the identical or highly similar argument have reached one of two conclusions: either that the Soo Line’s position is correct, or that the Soo Line’s position is arguably correct and must be committed to binding arbitration. It is difficult to conceive how a legal position such as the Soo Line’s, which has received such widespread judicial acceptance, could be deemed “frivolous” or “obviously insubstantial.”
Accordingly, the Soo Line has met its “relatively light burden.” Brotherhood of Maintenance of Way, 802 F.2d at 1022. We find this dispute to be minor and leave it to mandatory arbitration.
We are aware that two courts have concluded that individual lump-sum separation agreements may not coexist with preestab-lished collective agreements. Brotherhood of Railway, Airline and Steamship Clerks v. Chesapeake and Ohio Railway Co., 115 LRRM 3635 (N.D.Ohio 1983) [available on WESTLAW, 1983 WL 1754]; Southern Pacific Transportation Co. v. Brotherhood of Railway, Airline and Steamship Clerks, 636 F.Supp. 57 (D.Utah 1986). In concluding that the disputes were major, these courts found by necessity that management’s arguments as to the propriety of its actions were frivolous or obviously insubstantial. As we have tried to show, there is substantial case law which has sustained, or at least found non-frivolous, arguments similar to those made by management in these two cases. Accordingly, to the extent these cases apply to the situation before us, we decline to follow them.
Moreover, we believe these two cases are distinguishable. The Chesapeake and Ohio clerks had “bolted” positions after three years of service, which meant lifetime job protection. The pertinent collective bargaining agreement in the Southern Pacific case was a BRAC agreement similar, in its high level of protection, to the agreements in Chesapeake and Ohio. By contrast, in this case the IAM machinists were never “bolted.” In sum, the two cases are inapposite for the reason that their existing agreements provided a much higher level of protection for employees, thus in effect “closing the door” to a voluntary lump-sum separation plan, while the CBA and Protective Agreement in this case, by virtue of their silence on the subject, can coexist with a voluntary lump-sum separation plan.
C. Contractual Requirement of Arbitration.
There is another, equally persuasive reason why this case must go to arbitration rather than allowing the district court to *381vest status quo benefits in one of the parties while “disabling” the other party. The Protective Agreement provides in two places that “any dispute” over the “interpretation” or “application” of the New York Dock conditions (which are included as part of the Protective Agreement) must be resolved by binding arbitration before an expert railroad arbitation committee.12 Thus, the Protective Agreement, read as a whole, is unambiguous in requiring that any disputes arising with regard to its interpretation or application must be submitted to binding arbitration.
In Local No. 381, International Union of Operating Engineers v. Tosco Corp., 823 F.2d 265, 268 (8th Cir.1987), this circuit, quoting from the recently decided AT & T Technologies, Inc. v. Communications Workers of America, 475 U.S. 643, 650, 106 S.Ct. 1415, 1419, 89 L.Ed.2d 648 (1986), held:
[W]here the contract contains an arbitration clause, there is a presumption of arbitrability in the sense that “[a]n order to arbitrate * * * should not be denied unless it may be said with positive assurance that the arbitration clause is not susceptible of an interpretation that covers the asserted dispute. Doubts should be resolved in favor of coverage.”
(Emphasis added.) Tosco, again quoting from AT & T Technologies, went on to say that “[I]n deciding whether the parties have agreed to submit a particular grievance to arbitration, a court is not to rule on the potential merits of the underlying claims * * * even if it appears to the court to be frivolous * * Id. at n. 6. (Emphasis added.) In fact, the Supreme Court said in AT & T Technologies, 475 U.S. at 650, 106 S.Ct. at 1419, that where, as here, the arbitration clause refers broadly to any dispute over interpretation, “only the most forceful evidence of a purpose to exclude the claim from arbitration can prevail.” Moreover, as previously noted, this court has held that such language as is present in the Protective Agreement mandates compulsory arbitration.
The present dispute clearly falls within the applicable arbitration clauses as a dispute over the “interpretation” of the Protective Agreement. The following three aspects of the Protective Agreement require interpretation to resolve this dispute: (1) the preamble of the Protective Agreement provides that it only applies to employees “adversely affected by the Acquisition;” thus the term “affected” must be interpreted to determine if the eight machinists at issue here were so affected; (2) the preamble of the Protective Agreement seeks as a goal the operation of the expanded railroad “in the most efficient manner,” and this language must be interpreted to determine whether it comports with requiring the Soo Line to pay men to remain idle on furlough; and (3) the Protective Agreement as a whole must be examined to determine whether the absence of any language explicitly allowing or forbidding voluntary quits is more properly interpreted to allow or forbid such quits.
Stated more broadly, IAM’s main argument is that the Protective Agreement bars the Individual Plan; accordingly, to properly address IAM’s argument one must interpret the scope and meaning of the Protective Agreement, and the Protective Agreement states, not once but twice, that any dispute over its scope and meaning must go to binding arbitration. At a minimum, it certainly cannot be said “with positive assurance,” as Tosco requires, that this is not a dispute over the interpretation of the Protective Agreement. The New York Dock conditions themselves contemplate the “retirement” or “resignation” of even *382those employees who are otherwise eligible for protective payments. Article I, § 6(d) New York Dock conditions.
In sum, Tosco and AT & T Technologies require a court to ask whether there is “positive assurance that the arbitration clause[s]” — which expressly cover disputes over “interpretation” — are “not susceptible of an interpretation that covers the asserted dispute.” As we have noted at some length, adjustment boards have held that voluntary individual separation agreements do not violate labor agreements or the RLA. Federal courts have reached the same conclusion or have concluded that similar issues must be arbitrated. Yet, IAM argues here that the Individual Plan violates both the Protective Agreement and the RLA. Resolution of this issue can only be had by examining and interpreting the Protective Agreement. Directly contrary to IAM’s assertion, we think that the only response which can be set forth with “positive assurance” is that the arbitration clauses in this case are susceptible of an interpretation that covers the asserted dispute. Accordingly, the arbitration clauses must be given effect and allowed to operate over this dispute.13
In the final analysis, whether one relies upon the standard set out for distinguishing a major dispute from a minor dispute, or whether one relies upon the standard for determining whether arbitration clauses cover a dispute, the inquiry is essentially the same. That inquiry, in this case, is whether the Soo Line has set forth a position which is entitled to some credence. We conclude, in view of the cases which explicitly support the Soo Line’s position, as well as the pertinent language of the agreements, which arguably support the Soo Line’s position, that the Soo Line has more than met its burden under either inquiry.
III. CONCLUSION.
Although there is authority for the proposition that this case involves not a dispute, but rather, a choice personal to each employee, we rest our decision on the grounds that this is a dispute which is suitable for arbitration, both because it is a minor dispute and because the parties agreed to arbitration; therefore, we hold that the district court lacked jurisdiction to issue the injunction in this case. Accordingly, the judgment of the district court is reversed, the injunction is dissolved, and the case is remanded for arbitration.
. Moreover, as we will explain in greater detail, a pertinent agreement in this case contains arbitration clauses. As this court has stated:
[W]hen disagreement arises between the parties whether a particular dispute is arbitrable under the terms of the governing labor agreement, courts will broadly construe the agreement in favor of arbitrability, resolving doubts on the side of the board’s authority. United Steelworkers of America v. Warrior & Gulf Navigation Co., 363 U.S. 574, 582-83, 80 S.Ct. 1347, 1352-53, 4 L.Ed.2d 1409 (1960); Zeviar v. Local 2747, [Airline, Aerospace and Allied Employees, 733 F.2d 556, 559 (8th Cir.1984) ]; Lackawanna Leather v. United Food & Commercial Workers, 706 F.2d 228, 230-31 (8th Cir.1983) (en banc).
Ozark Air Lines, Inc. v. Air Line Pilots Association, Int'l, 744 F.2d 1347, 1350 (8th Cir.1984), aff’d en banc by an equally divided court, 761 F.2d 1259, cert. denied, 474 U.S. 903, 106 S.Ct. 232, 88 L.Ed.2d 231 (1985).
. The panel opinion previously filed, 833 F.2d 730 (8th Cir.1987), was withdrawn and vacated when the petition for rehearing en banc was granted.
. Section 11347 requires the carrier to provide a fair arrangement at least as protective of the interests of employees as the terms imposed under section 11347 prior to February 5, 1976 (the date the section was amended) as well as those established under section 405 of the Rail Passenger Service Act, 45 U.S.C. § 565.
. Section 11 of the New York Dock conditions contains a mandatory arbitration clause which provides, in pertinent part:
11. Arbitration of disputes. — (a) In the event the railroad and its employees or their authorized representatives cannot settle any dispute or controversy with respect to the interpretation, application or enforcement of any provision of this appendix, * * * it may be referred by either party to an arbitration committee.
This court has recently held that arbitration clauses identical to those at issue here mandate compulsory arbitration of "any dispute" between the parties relating to New York Dock protections. Hoffman v. Missouri Pacific Railroad, 806 F.2d 800, 801 (8th Cir.1986). Even *372though these arbitration clauses say disputes "may" be referred to arbitration, the clauses nevertheless make the arbitration both mandatory and binding. Hoffman, 806 F.2d at 801.
. As explained by the court in Matter of Chicago, 799 F.2d at 329:
The principal difference between the "Appendix B" conditions [those conditions actually imposed in this case] and the New York Dock conditions is that although New York Dock requires the railroad to notify employees of impending changes 90 days in advance, and to negotiate with the unions concerning their consequences until agreement is reached, "Appendix B” shortens the time to ten days and allows the railroad to make the changes whether or not the unions consent. "Appendix B" also requires that any employee injured by this accelerated schedule be made whole. See In re Chicago, Milwaukee, St. Paul & Pacific R.R., 658 F.2d 1149, 1151-52 (7th Cir.1981) (Protective Conditions), cert. denied, 455 U.S. 1000, 102 S.Ct. 1632, 71 L.Ed.2d 867 (1982), for a description of the difference.
For purposes of clarity in this opinion, the conditions imposed will be referred to as the New York Dock conditions.
. IAM asserts that these discussions were tantamount to formal negotiations, and by proceeding in formal negotiations, the Soo Line acknowledged that this was a subject of mandatory bargaining. In our view this misinterprets the record. In an affidavit, the Senior Vice President for Labor Relations and Personnel for the Soo Line stated that the discussions only occurred with the understanding that they were without prejudice to the Soo Line’s rights to unilaterally accept separation requests from machinists. Moreover, we know of no rule that requires the transformation of an issue into a major dispute under the RLA merely because discussions take place that could be characterized as "negotiations.”
. The district court’s analysis of this issue is as follows:
If these company/individual agreements were to be allowed, the union would be denied the right of access to formal negotiation concerning compensation for severance; a right secured to it by Section 6. Further, these events occur in a setting in which an existing furlough plan is in place. Under these conditions, the Court finds that Soo Line's conduct violates the RLA and its underlying policies.
District Court Order at 8.
. We note by analogy that “[a]s a general rule, federal courts do not have jurisdiction over activity [that] is ‘arguably subject to § 7 or § 8 of the [NLRA],’ and they ‘must defer to the exclusive competence of the National Labor Relations Board.’ ” Kaiser Steel Corp. v. Mullins, 455 U.S. 72, 83, 102 S.Ct. 851, 859, 70 L.Ed.2d 833 (1982) (quoting San Diego Building Trades Council v. Garmon, 359 U.S. 236, 245, 79 S.Ct. 773, 779, 3 L.Ed.2d 775 (1959)). Section 7 of the NLRA, 29 U.S.C. § 157, generally provides that employees have the right to join, or refrain from joining, unions. Section 8 of the NLRA, 29 U.S.C. § 158, generally defines unfair labor practices by both employers and unions.
. Both dissents assert that implementation of the Individual Plan will result in employee and work transfers, will affect seniority and bidding rights of other IAM members, and will probably deprive some employees of the opportunity to be separated under the terms of the Protective Agreement. We can find no support in the record for these predictions. In fact, in an affidavit, the General Chairman of IAM stated that any current or future furloughs, transfers, and work reductions resulted from the Acquisition, not the Individual Plan. Accordingly, under the broad definitions of "affected" or "displaced” employees in the Protective Agreement and New York Dock conditions, any employees furloughed or transferred would become eligible for benefits under the Protective Agreement and would in no way be harmed by the Individual Plan. As to seniority rights, any effect that the Individual Plan has will be positive, not negative, for if employees opt for the Individual Plan, the seniority of remaining Union members will be increased. Moreover, the presence of the Individual Plan will not deprive any employees of the opportunity to be separated under the terms of the Protective Agreement, for the simple reason that an employee who opts for the Individual Plan is not being deprived, but is making a free choice. An employee who decides against the Individual Plan remains as eligible as ever for the benefits of the Protective Agreement.
.Judge Heaney argues in dissent that by negotiating the Individual Plan, the Soo Line reduced its obligations under the Protective Agreement, while benefitting select IAM members to the detriment of those members who would have otherwise qualified for benefits under the Protective Agreement. The dissent apparently finds fault with the Soo Line for trying to avoid the prospect of paying people to sit at home. In our view this argument downplays a key consideration, namely that the Individual Plan is completely voluntary. An employee who decides not to seek the Individual Plan remains as eligible as ever for benefits under the Protective Agreement, if affected by the Acquisition. Had the eight employees at issue been eligible for the greater benefits offered by the Protective Agreement, they would have opted for the Protective Agreement, entailing as it did benefits more than double those of the Individual Plan. These near-retirement employees had such vested seniority rights that it is dubious whether they *378would have been "affected" by the Acquisition. Thus the existence of the Individual Plan did not detract from rights that they otherwise had under the Protective Agreement, but rather, gave them rights which they otherwise could not have claimed under the Protective Agreement.
When one looks at the practicalities of the railroad seniority system, an ancillary reason for the Union's complaint becomes apparent. As a result of the Acquisition, the Protective Agreement required that those machinists with less seniority were furloughed first and were being paid a day's wages for not working; however, when the senior eight machinists quit and took the $15,000, the seniority of the junior machinists was increased by eight and some or all of them may have gone off furlough and back in service. The Union’s efforts, which would result in the Soo Line's paying junior machinists to remain on furlough, hardly comports with the preamble in the Protective Agreement signed by the Soo Line and the Union to "provide for expedited changes” to allow operation of the Soo Line "in the most efficient manner."
. In this case, neither side makes any argument regarding past practice, or a lack thereof, with regard to the offering of lump-sum separation plans. Accordingly, past practices play no part in our decision. We note, however, that when employees of the Soo Line are injured they have the right to make claim and commence suit under the provisions of the Federal Employer’s Liability Act (FELA). Soo Line has been negotiating settlement agreements with injured employees for over fifty years pursuant to the FELA, whereby an injured employee negotiates directly with the railroad to terminate his employment for consideration. These settlements have always been between the Soo Line's Claim Department or the Soo Line’s Law Department and the employee (with or without an attorney), without any involvement by the labor organizations.
. Article 1, § 11 of the New York Dock conditions provides: "In the event the railroad and its employees or their authorized representatives cannot settle any dispute or controversy with respect to the interpretation, application or enforcement of any provision [herein] * * *, it may be referred by either party to an arbitration committee." (Emphasis added.)
Section 8 of the Protective Agreement provides that “any dispute or controversy with respect to the interpretation [or] application * * * of this Agreement * * * may be referred by any party to an arbitration board [under] Article I, Section 11 of the New York Dock Conditions.”
As noted previously, see supra n. 4, such language has been held by this circuit to impose mandatory arbitration.
. Even apart from the arbitration clauses at issue, the RLA itself requires arbitration of the instant dispute. Section 3 of the RLA requires arbitration by expert adjustment boards of any dispute over the "interpretation or application" of railway labor agreements. 45 U.S.C. § 153 First.