General Marine Transport Corp. (“General Marine”) petitions this court pursuant to Section 10(f) of the National Labor Relations Act (“NLRA” or “the Act”), 29 U.S.C. § 160(f), to review and set aside an order of the National Labor Relations Board entered on September 29, 1978 which adopted the recommendation of Administrative Law Judge David S. Davidson. The Board ruled that General Marine had engaged in unfair labor practices by repudiating a multi-em-ployer association contract and by making unilateral changes in wages, hours and other terms and conditions of employment in violation of Section 8(a)(5) and (1) of the Act, 28 U.S.C. § 158(a)(5) and (1). The Board cross-petitions for enforcement of its order. Because we find that the complaint from which this enforcement proceeding arises is time-barred by virtue of section 10(b) of the Act, 29 U.S.C. § 160(b), the petition for review is granted, the order set aside, and the cross-application for enforcement denied.
Statement of Facts
A somewhat detailed review of the dispute between General Marine and the inter-venor in this proceeding, United Marine Division Local 333 I.L.A., A.F.L.-C.I.O. (“Local 333”), is necessary for an understanding of the issues, particularly the statute of limitations issue, raised in this case. *182General Marine, a wholly-owned subsidiary of a holding company owned and operated by the Berman Family, operates sludge vessels used to transport and dispose of sewage sludge. Sometime prior to 1973, General Marine recognized Local 333 as the collective bargaining representative of its employees and joined the New York Marine Towing and Transportation Association (“the Association”), a multiemployer association which negotiates contracts on behalf of its members with the union. In 1969, General Marine agreed that all Association contracts listing it as a member would apply to employees working five vessels — the Susan Frank, the Sam Berman, the Samantha, the Richard K, and the Jonathan B (hereinafter “the 1969 letter of understanding”). On April 1, 1973, the Association, on behalf of owners of towing and transportation vessels, including General Marine, entered into a three year contract with Local 333. Article I Section I of the agreement limited its scope “to licensed and unlicensed employees, employed on tugboats and self-propelled lighters owned or operated by the [covered employers] in the Port of New York and vicinity.”
Shortly before the expiration of the 1973-76 contract, the Association requested General Marine to complete an authorization form so that the Association could negotiate a new contract on its behalf. The president of General Marine signed the form and, in response to a request for the “number and type of vessels that your company . . . now owns or operates which are subject to the union agreements,” the president listed one vessel — the Susan Frank. On March 26, 1976, the Association and Local 333 executed a new three year contract which, with the exception of two provisions, renewed the 1973-76 agreement. These two changes were as follows. First, the new agreement covered not only all employees working on vessels owned or operated by member employers, but also all employees of “a subsidiary company, an affiliated company or a company division in the Port of New York and vicinity.” Second, the new agreement contained the so-called vegetable oil clause which stated that:
[n]o vessel operated under this contract shall tow any barge under 55,000 barrels used in the animal, vegetable, or fish oil trades unless there are two men aboard the barge at all times.
Based upon this agreement, Local 333 claimed that Berman Enterprises, Inc. (“Berman”), a corporation which operates tugs, barges, and tankers in the New York harbor and which, like General Marine, is a wholly-owned subsidiary of the Berman family holding company, was required to abide by the contract between the Association and the union. On April 13, 1976, Peter Frank, Vice President of General Marine, sent a letter to Local 333 which stated, in pertinent part:
We have studied [the agreement] and find that its scope exceeds the authority of the Association to negotiate on behalf of General Marine Transport Corp. In addition, the Memorandum, among other things agrees to conduct that constitutes an unlawful group boycott.
As a result of these provisions this company cannot bind itself to the memorandum of Agreement and will not execute a collective bargaining agreement based upon its term.1
Between April and August 1976, Local 333 filed four separate charges with the Board, claiming that both General Marine and Ber-man had engaged in unfair labor practices. The first charge (Case No. 2-CA-14240), filed on April 23, 1976, stated that Berman and its affiliated companies, including General Marine, abrogated the 1976-79 Association contract by sending the April 13th letter to Local 333, thereby indicating a refusal to bargain fairly with the employee rep*183resentative in the appropriate bargaining unit. The Regional Director refused to issue a complaint in this matter. In a letter dated June 16, 1976, she explained to the union the reasons for her decision:
The investigation discloses that for many years past the only company named in the charge which had been a party to the aforesaid Association agreements was General Marine ... It appears further from the evidence, that your recent efforts to secure a new contract from General Marine, included a demand that the unit of employees historically represented by you, as noted above, be enlarged to encompass employees and vessels of the various affiliated companies, which employees could not, at this time, appropriately be included in the historical unit . . . Under these circumstances, the refusal by any of the charged parties to execute the Association agreement cannot be deemed to constitute a violation of the Act as alleged by you.
The Regional Director also supported her decision based upon the determination that the vegetable oil clause was an illegal hot cargo clause and called for a group boycott:
Moreover, this agreement contains a provision which the General Counsel has concluded is in violation of Section 8(e) of the Act and is the subject of further proceedings in Case No. 2-CE-93.
The General Counsel of the Board denied Local 333’s appeal in July 1976 and its request for reconsideration in August 1976 “substantially for the reasons set forth in the Regional Director’s letter . . . ”
Local 333 filed a second charge (Case No. 2-CA-14246) on May 18, 1976, stating that General Marine and Berman had refused to bargain, had induced employees to become members of another union, District No. 1— Pacific Coast District, Marine Engineers Beneficial Association, A.P.L.-C.I.O. (“MEBA”), and had conspired with MEBA to achieve this end. On June 30, 1976, two days after the Regional Director had determined that a complaint should issue alleging unlawful employer assistance,2 Berman entered into a settlement agreement with the Board in which Berman agreed, inter alia, not to recognize MEBA as its employees’ bargaining representative until the Board held an election following a representation proceeding that Berman had commenced on June 11, 1976.
Local 333 filed yet another set of charges on August 6, 1976, once again naming Ber-man and all its affiliates. The charge in Case No. 2-CA-14433-1 stated that the employers abrogated the 1976-79 Association contract by the April 13th letter and thereafter refused to bargain with the union with respect to the employees working on four vessels — the Rebecca K, Susan Frank, Sam Berman, and Richard K.
The charge in Case No. 2-CA-14433-2 set forth identical claims except that they were directed only to employees of three ships replacing vessels listed in the 1969 letter agreement. On August 12,1976, Ber-man requested dismissal of these charges on the grounds that they were identical to the previously dismissed charges raised in Case No. 2-CA-14240 and because the settlement agreement in Case No. 2-CA-14246 effectively precluded Berman from entering into an agreement with any union until the representation question was resolved by the Board. Before the Board could act on Berman’s request, Local 333 contacted the Regional Director and offered to withdraw the charges. On August 23rd, the Regional Director approved this request.
Having been unsuccessful with its unfair labor practice charges, the president of Local 333 wrote to Jared Stamell, general counsel for the Berman-owned enterprises, on August 18, 1976 stating that “demand is hereby made upon you to collectively bargain concerning the terms and conditions of our labor contract involving the vessels acknowledged to be within the bargaining unit by the 1969 letter [agreement]. Stamell responded to the union’s *184counsel on August 30th in pertinent part as follows:
Dear Mr. Altier:
I have received Local 333, United Marine Division’s letters to Berman Enterprises Inc. and other corporations demanding collective bargaining.
I am reviewing the demand on behalf of the corporations in light of the recent activities before the National Labor Relations Board, and the companies will respond directly to the union concerning the demand shortly.
On October 26, 1976, Berman’s controller, Susan Frank, wrote to Local 333, advising the union that Berman believed that its August 18th demand was inappropriate because the representation issue was still pending and because the settlement agreement in Case No. 2-CA-14246 precluded Berman from recognizing or bargaining with any union until a board election had been held.
Hearings were held in the representation proceeding during September and October 1976 and the Regional Director issued her decision on December 10, 1976. The Regional Director first reviewed the history of the coverage of Association contracts and found that only three of the vessels that were named in the 1969 letter of understanding were still owned by either Berman or General Marine.3 She further found that the 1973-76 Association contract had been applied only to the crews of the two ships either owned or operated by General Marine, the Susan Frank and the Rebecca K,4 and not any Berman vessels. The Regional Director concluded that the 1976-79 Association contract applied to the employees aboard these two vessels because General Marine had not withdrawn in a timely manner from the Association and thus that the contract was a bar to the election petition insofar as the petition purported to include these employees. The Regional Director rejected Local 333’s contention that the 1976-79 Association contract was also binding on Berman and therefore was a bar to an election among Berman employees. Berman, the Regional Director noted, neither executed any document authorizing the Association to act on its behalf nor evidenced its desire to be a part of the multi-employer association by applying the terms of the contract to its employees. Accordingly, the Regional Director ordered that an election be conducted in a unit consisting of “the employees employed by Berman to man the various vessels it operates . . . and [not including] the employees manning the two sludge vessels operated by General Marine . . . ”
Local 333 alone filed a request for review of the Regional Director’s decision and direction of election. The Board denied the request on January 10,1977. Shortly thereafter, the election was held, and on January 20, 1977, the Regional Director certified MEBA as the representative of employees on the vessels of Berman and its affiliates other than the Susan Frank and the Rebecca K.
Between January and March 1977, Local 333, with the representation question settled, demanded that General Marine honor the terms of the Association contract. In a letter dated January 19, 1977, Local 333 wrote:
You have withheld pension insurance payments for these employees since last April during pendency of the Labor Board case. We herewith demand that said payments be reinstituted, including all arrears with interest from their due date.
Local 333 reiterated this request by letter dated February 11, 1977. A union official also telephoned General Marine’s vice president, Peter Frank, on three occasions during this period. In each case, he was told that Frank was unavailable and spoke with the general counsel for Berman-owned enterprises. The union official again ex*185plained that General Marine owed pension and welfare payments to the union and insisted that it abide by the terms of the Association contract with Local 333.
On February 28, 1977, Local 333 filed a final unfair labor practice charge (Case No. 2-CA-14735) and the charge from which this enforcement proceeding arises. Unlike the previous four charges, this charge only named General Marine. On June 16, 1977, exactly one year after her dismissal of the first charge, the Regional Director determined that a complaint should issue, alleging that General Marine refused to bargain with Local 333 and violated Section 8(a)(5) and (1) by not abiding by the wage rates and pension and welfare contributions as set forth in the 1976-79 Association contract.
Administrative Law Judge David S. Davidson held a hearing on this matter in February 1978 and issued his decision on June 27, 1978. The ALJ determined that General Marine was foreclosed, pursuant to section 102.67(f) of the Board’s Rules and Regulations,5 from further litigating the issue of the validity of the Association contract since that issue either was or could have been raised in the representation proceeding in which the Regional Director confronted the issue of whether or not the Association contract was a bar to an election among General Marine employees. The ALJ also determined, notwithstanding General Marine’s initial repudiation of the Association contract by its letter of April 13, 1976, that the instant complaint was not time-barred by virtue of the six month limitation period set forth in section 10(b) of the NLRA. The ALJ offered two reasons for this conclusion. First, the Regional Director’s December 1976 ruling that the Association contract was a bar to an election among General Marine employees, according to the ALJ, altered the circumstances to such an extent that it completely vitiated General Marine’s prior repudiation. The AU therefore reasoned that Local 333’s letters and phone calls between January and March of 1977 constituted fresh demands within a narrower bargaining unit and that General Marine’s subsequent refusals constituted new repudiations of both the Association contract and its obligation to bargain. Secondly, the ALJ advanced what may be characterized as an estoppel theory: “[hjaving pleaded pendency of the petition as a reason not to apply the contract previously [General Marine] cannot now be heard to argue that its failure to apply the agreement after the Regional Director’s decision was merely a repetition of its earlier conduct and not an unfair labor practice within the 10(b) period.” Because the parties stipulated that General Marine failed to comply with several provisions in the contract since September 1976, and having already determined that the validity of the contract could not be relitigated and that the complaint was timely, the ALJ held that General Marine violated Section 8(a)(5) and (1) of the NLRA and recommended that General Marine be ordered to comply with the terms of the Association contract.
General Marine filed exceptions to the ALJ’s recommendation and a motion to reopen the record. In addition, counsel for General Marine requested leave to withdraw. By letter dated September 21, 1978, the Associate Executive Secretary of the Board notified General Marine that the Board had granted the request of counsel to withdraw as well as an extension until October 16, 1978 for new counsel to submit additional argument on the pending motion. Eight days later, however, the Board, without notice to General Marine, summarily affirmed the decision and recommended order of the ALJ. General Marine’s new *186counsel continued to pursue his motion for reconsideration and to reopen the record.6 On January 29, 1979, an order executed under the direction of the Board by its Associate Executive Secretary denied both motions.
Discussion
In support of its petition to set aside the Board’s order, General Marine argues that (1) the complaint is time-barred under section 10(b) of the NLRA because the union filed and served its charge more than six months after the occurrence of the unfair labor practice upon which the complaint is based, (2) the Board violated General Marine’s statutory and constitutional rights by foreclosing it from litigating the validity of the Association contract in the unfair labor practice proceeding and (3) the denial of the motion to reopen the record and to reconsider was improper since the Board itself did not decide the motion and because the reasons for the denial were not stated. Because we agree that the complaint is time-barred, we need not consider the remaining issues.
Local 333 filed the charge from which this enforcement proceeding arises on February 28, 1977 and served it on General Marine on March 2,1977.7 Thus, the resulting complaint is timely only if the underlying unfair labor practice occurred on or after September 1, 1976. General Marine maintains that the complaint is time-barred since the charge was not filed until almost eleven months after the occurrence of the unfair labor practice — General Marine’s initial repudiation of the Association contract on April 13, 1976. This position rests in large part on the Supreme Court’s decision in Local Lodge 1424 International Association of Machinists v. NLRB, 362 U.S. 411, 80 S.Ct. 822, 4 L.Ed.2d 832 (1960). In Local Lodge, a union committed a violation of the NLRA by entering into a collective bargaining agreement containing a union security clause at a time when it did not represent a majority of the employees in the appropriate unit. Charges were filed with the Board ten to twelve months after the execution of the agreement. Conceding that a complaint predicated on the execution of the agreement was time-barred, the Board nevertheless argued that the parties’ continued enforcement of the agreement was a separate and continuing unfair labor practice not barred by section 10(b). The Court disagreed, holding that continued enforcement of the contract was not an unfair labor practice without reference to the unlawful execution of the bargaining agreement which had occurred more than six months prior to the filing of the charge. Thus, this was not a situation in which events ante-dating the six month period were being used solely to “shed light” on the events occurring within the limitations period. Instead, the case involved, according to the Court, an unfair labor practice that was “inescapably grounded” on a time-barred event. Id. at 422, 80 S.Ct. at 829.
The continuing violation theory that was rejected in Local Lodge fares no better when the alleged unfair labor practice is an agreement’s continued repudiation rather than its continued enforcement. In the instant case, the complaint alleges that General Marine engaged in unfair labor practices by continuing to repudiate the Association contract and unilaterally changing ex*187isting wage rates, hours of employment, pension and welfare contributions, and other terms and conditions of employment. See Joint Appendix at 5 IK 7-9. Just as the Local Lodge complaint was based upon the time-barred execution of a bargaining agreement, the complaint at issue here unequivocally derives from the time-barred initial repudiation of the Association contract. Other circuits have agreed that an employer’s repeated repudiations of a multi-employer association contract constitute neither an unfair labor practice nor give rise to a cause of action with a separate limitation period. See NLRB v. Serv-All Co. Inc., 491 F.2d 1273, 1275 (10th Cir. 1974); NLRB v. McCready and Sons, Inc., 482 F.2d 872, 874-876 (6th Cir. 1973); NLRB v. Field and Sons, Inc., 462 F.2d 748, 750 (1st Cir. 1972); contra NLRB v. Strong, 386 F.2d 929, 931 (9th Cir.), cert. denied 390 U.S. 920, 88 S.Ct. 853, 19 L.Ed.2d 980 (1968).
We recognize, as did the ALJ, that an employer’s conduct or intervening circumstances can alter the grounds upon which the initial repudiation is based to such an extent as to make subsequent repudiations fundamentally separate unfair labor practices with their own limitation periods. See NLRB v. McCready and Sons, Inc., supra at 875 n.3. We conclude, however, that neither General Marine’s actions nor events occurring after its April 13,1976 repudiation changed the circumstances to so great an extent. General Marine initially refused to execute the Association contract on at least two grounds: (1) that the Association exceeded the scope of its authority by entering into a contract which bound not only General Marine but also its “affiliates”, i. e. Berman, and (2) that the vegetable oil clause constituted an unlawful group boycott. The Regional Director’s December 1976 ruling undisputedly resolved the question of the scope of the contract and, in so doing, eliminated it as a possible basis for General Marine’s continued repudiations. However, it could not have resolved the hot cargo clause issue since “[i]t is well settled that contentions of this nature are not liti-gable in a representation proceeding.” Buckeye Village Market, Inc., 175 NLRB 271, 272 (1969), citing, inter alia, Food Haulers, Inc., 136 NLRB 394, 396 n.6 (1962). See also Kroger Co., 165 NLRB 872, 881 (1967) (“[t]he limited scope of a representation case and the basic focus of such a case is illustrated by the fact that a contract containing a ‘hot cargo’ clause, unlawful under Section 8(e) of the Act has nevertheless been held to be a bar [to an election]”), citing Food Haulers, Inc., supra.8 Indeed, the Regional Director’s thorough decision, *188ostensibly in conformity with these precedents, made no findings with respect to the validity of the contract or any clause therein.9 After a review of the historical coverage of Association contracts, the Regional Director held only that “the 1976-79 Association contract is a bar to the petition insofar as the petition purports to include vessels owned or operated by General Marine including the Susan Frank and the Rebecca K.” Thus, when General Marine continued to repudiate the Association contract throughout January and February 1977, one of its two unambiguous and independent reasons for the initial repudiation had not been altered by any intervening Board action. Accordingly, the company’s continued repudiations were only a repetition of its earlier conduct rather than a separate unfair labor practice.
The ALJ determined, however, that General Marine was estopped from making this argument since it had relied on the penden-cy of the representation petition to deflect the union’s demands. This is a misstatement of the facts because it was Berman, not General Marine, which followed this course of conduct. On June 30, 1976, two days after the Regional Director determined that a complaint should issue against Berman and its affiliated companies in Case No. 2-CA-14246, only Berman entered into a settlement agreement in which it agreed not to recognize any labor organization until the conclusion of the representation proceeding and a Board certified election. The General Counsel eliminated any doubt that could exist with respect to this point by noting at the hearing before the AU that “the only signatory to the settlement agreement is Berman Enterprises and according to the [Regional Director’s decision in the representation proceeding], Berman is something distinct from General Marine.”
In August 1976, Local 333 wrote to Jared Stamell, general counsel for the Berman-owned enterprises, again to request compli-anee with the terms of the collective bargaining agreement. Although Stamell stated that he was “reviewing the demand on behalf of the corporations,” he concluded by saying that “the companies will respond directly to the union concerning the demand shortly (emphasis added).” Berman did so on October 26, 1976. Susan Frank, the company’s controller wrote:
As you know, a petition for an election . is pending before the National Labor Relations Board. Furthermore, this company is precluded by the settlement agreement in the charge brought by . Local 333, from recognizing and bargaining with any union until after an NLRB election has been held.
Under these circumstances, we believe that your demand is inappropriate and we ask that you withdraw it.
Very truly yours,
BERMAN ENTERPRISES, INC.
(emphasis added). Nothing in this letter indicates that Berman was speaking both for itself and on behalf of General Marine. In fact, the clear wording of the letter is to the contrary. Moreover, we are particularly wary to read this statement as an expression of General Marine’s view since the gravamen of the tortured proceedings between the employers and Local 333 revolved around the non-recognition of the separate representational status of the employees working on Berman vessels. Finally, even assuming for the sake of argument that these letters could be considered somewhat equivocal, neither rises to the level of the kind of affirmative misrepresentations traditionally deemed essential for a party to be estopped from asserting a statute of limitations defense. See, e. g. Note, Developments in the Law — Statute of Limitations, 63 Harv.L.Rev. 1178, 1220-21 & n.354 (1950).
In short, we find that Local 333 could have filed the instant charge any time after *189April 13, 1976, see Nazareth Regional High School v. NLRB, 549 F.2d 873, 882 (2d Cir. 1977); Local 1104, Communication Workers v. NLRB, 520 F.2d 411, 416 (2d Cir. 1975), cert. denied 423 U.S. 1051, 96 S.Ct. 778, 46 L.Ed.2d 639 (1976) and that nothing relieves it from its failure to do so within six months from that date. The intervenor argues that it was understandably unsure of the vessels covered by the Association contract and the companies to which it should have addressed its demand. This uncertainty may explain its reason for deciding to make a demand in a unit consisting of Berman and all its affiliated companies in the first charge filed ten days after the initial repudiation. However, it clearly does not explain why the union persisted in making demands in a broadened unit after the Regional Director twice refused, as early as June 1976, to issue complaints related to the repudiation of the contract on the ground that affiliated companies simply “could not . . . appropriately be included in the historical unit . . . ” Based upon this clear direction, we do not believe that this case presents a situation, as the dissent suggests, in which the union was compelled to file separate and admittedly wasteful charges “covering every possible combination of employees it claimfed] to represent” in order to be assured that it filed a timely charge in the appropriate bargaining unit as later determined at the representation hearing.
Accordingly, the petition for review is granted, the order set aside, and the cross-application for enforcement denied.
. General Marine sent a virtually identical letter to the Association on the same date. The only difference between the two letters is that the letter to the Association qualified its objection to the scope of the contract by stating that the agreement contains provisions that “further the interests of other members of the Association at the expense of General Marine Transport Corp.”
. The Regional Director refused, however, to issue a complaint with respect to the portion of the charge alleging a refusal to bargain for “substantially the same . . . reasons” as stated in her dismissal letter of June 16, 1976 regarding Case No. 2-CA-14240.
. These three vessels were the Susan Frank, owned by General Marine, and the Sam Ber-man and the Richard K, sold by General Marine to Berman in 1971 and 1973 respectively.
. General Marine began operating the Rebecca K after it submitted the authorization form in March 1976 to the Association.
. Section 102.67(f) of the Board’s Rules and Regulations provides:
The parties may, at any time, waive their right to request review. Failure to request review shall preclude such parties from reliti-gating, in any related subsequent unfair labor practice proceeding, any issue which was, or could have been, raised in the representation proceeding. Denial of a request for review shall constitute an affirmance of the regional director’s action which shall also preclude relitigating any such issues in any related subsequent unfair labor proceeding.
. General Marine moved for reconsideration on two grounds: (1) that the Regional Director’s ruling in the representation proceeding that the contract was a bar to an election did not determine its validity and (2) that the ALJ’s refusal to hear testimony concerning events occurring prior to September 1, 1976 — the beginning of the section 10(b) period — was material error. The basis for the motion to reopen the record was to introduce evidence obtained in an antitrust action commenced by General Marine against Local 333, the Association, and certain members of the Association.
. At the hearing before the ALJ, the petitioner was unable to offer the return receipt of the mailing of the charge and thus establish conclusively the date upon which it mailed the charge to Local 333. The ALJ found, however, that other proof offered by General Marine “was sufficient to support an inference that a copy of the charge was mailed on March 2 and thereafter received.”
. At oral argument, the Board and Local 333 contended that Food Haulers does not stand for as broad a proposition as the Board cited it for in its brief: that “the existence of a boycott provision unlawful under Section 8(e) of the Act is not a matter which is relevant to or contemplated by a contract bar determination” (Respondent’s Brief at 18-19). Instead, they argue that the validity of a group boycott clause would be litigable in a representation proceeding only if the provision, unlike the one included in the 1976-79 Association contract, appeared to be “so basic to the whole scheme of [the] contract and so interwoven with all its terms that it must stand or fall as an entirety.” See NLRB v. Rockaway News Supply Co., 345 U.S. 71, 78, 73 S.Ct. 519, 523, 97 L.Ed. 832 (1953). Although this position illustrates that General Marine may not have been able to defend against refusal to bargain charges based upon the inclusion of the hot cargo clause in the repudiated contract, see dissenting opinion at p. 192, it concedes that the validity of the clause could not have been litigated before the Regional Director.
Local 333 also argues that Food Haulers and the other cases relied on by the petitioner only hold that a Regional Director’s rejection of a contract bar defense in a representation hear-injg does not amount to a finding of contract validity for all other purposes. These cases do not establish, according to the union, that a Regional Director’s finding of a contract bar does also determine the validity of the contract. We disagree. In Food Haulers, the Board held that a contract containing a hot cargo clause barred an election. In reaching this result, the Board noted that “it has consistently refused to permit litigation of unfair labor practice issues in representation proceedings. The exception was made in the case of unlawful security cases [C. Hager & Sons Hinge Manufacturing Co., 80 NLRB 163 (1948)], as pointed out above, because such clauses — unlike the clause here in issue — impinge directly upon an employee’s free choice of bargaining representative, which a representation proceeding is designed to ascertain.” Food Haulers, Inc., supra, at 396 n.6.
. The union’s statement that “extensive evidence was also adduced at the representation hearing concerning . the incidents leading to the alleged hot cargo clause dealing with towing vegetable oil clause” (Intervenor’s Brief at 21-22) is not to the contrary. Our examination of the pages cited by the union for the above-quoted assertion indicates that the issue of the legality of the vegetable oil clause was hardly raised, let alone fully litigated.