Appellants, the United Association of Journeymen and Apprentices of the Plumbing and Pipe Fitting Industry of the United States and Canada with its Local Uni*166ons Nos. 469, Phoenix, and 741, Tucson, comprised substantially all of the journeymen and apprentice employees engaged in the performance of plumbing services in the State of Arizona. They entered into a collective bargaining agreement with appellant, Associated Plumbing Contractors of Arizona, which agreement governs the rates of pay, hours of employment and working conditions of substantially all plumbing operations in the building and construction business in the State. Appellees were at the time of the commencement of this action engaged in the business of contracting plumbing and pipe fitting services and commodities; intervening appellees were engaged in the business of air conditioning refrigeration, sheet metal and pipe fitting. Some of appellees were originally members of the Associated Plumbing Contractors but withdrew prior to the instigation of this action; the remaining appellees and intervening appellees entered into separate agreements with the unions upon the same terms and conditions as the collective bargaining agreement between Associated Plumbing Contractors and the unions. The collective bargaining agreement between the Associated Plumbing Contractors and United Association and its Locals was modified by mutual consent on or shortly prior to June 28, 1954, to, among other things, increase the rate of pay 20^ per hour and establish a benefit fund based on the rate of per hour per employee. On that day the unions advised all the appellees by written communication that the modifications were also effective as to each of them retroactive to the 20th day of June, 1954.1
The lower court found that a conspiracy existed between the unions and the Association of Plumbing Contractors for the purpose of wrongfully compelling the appellees and intervening appellees to modify their agreements to conform to the modified agreement entered into with the Association of Plumbing Contractors. No finding was made as to the effect of appellees’ business on interstate commerce, the court apparently adopting the view that since the acts complained of were breaches or attempted breaches of contract it had jurisdiction to grant the relief sought. By way of relief the court issued pendente lite orders restraining appellants from in any manner inducing, inciting, compelling or attempting to induce, incite or compel appellees and intervening appellees to accept or recognize any amendments or additions to their collective bargaining agreements and further restraining appellants from inducing, inciting, compelling or attempting to induce, incite or compel the *167employees of appellees and intervening appellees from working or continuing to work except in accordance with the terms and conditions of the agreements.
Appellees have moved to dismiss this appeal for the reason that appellants’ assignments of error do not conform to the rules of this court, Rule 5(c), citing Ramirez v. Burrell, 77 Ariz. 1, 266 P.2d 390. It is our conclusion, however, that certain of the assignments of error, particularly those questioning the want of jurisdiction of the court below are sufficient when examined in conjunction with appellants’ propositions of law. In re Balke’s Estate, 68 Ariz. 373, 206 P.2d 732. Accordingly, the motion to dismiss is denied.
The controlling question which disposes of this appeal is whether the Superi- or Court of Maricopa County, Arizona, has jurisdiction to issue an injunction restraining the unions from attempted unilateral modifications of collective bargaining agreements under the particular circumstances of this case as above set forth and as hereafter supplemented. We think the Superior Court did not have such jurisdiction.
The construction industry is an “industry affecting interstate commerce”, National Labor Relations Board v. Denver Building & Construction Trades Council, 341 U.S. 675, 71 S.Ct. 943, 95 L.Ed. 1284; National Labor Relations Board v. Reed, 9 Cir., 206 F.2d 184; Shore, for and on Behalf of N.L.R.B. v. Building & Construction Trades Council, 3 Cir., 173 F.2d 678, 8 A.L.R.2d 731; United Brotherhood of Carpenters, etc. v. Sperry, 10 Cir., 170 F.2d 863; Douglas v. International Brotherhood of Electrical Workers Union, D.C., 136 F. Supp. 68.
The interstate character of commerce is not decided simply by considering the quantitive effect of the activities of a particular employer.
“ * * * Appropriate for judgment is the fact that the immediate situation is representative of many others throughout the country, the total incidence of which if left unchecked may well become far-reaching in its harm to commerce.” Polish Nat. Alliance of United States of North America v. National Labor Relations Board, 322 U.S. 643, 64 S.Ct. 1196, 1199, 88 L.Ed. 1509.
“The Shore Case, * * * and other authorities seem clearly to hold that what affects the building industry in any community really affects interstate commerce, even though an unfair labor practice and a stoppage of work in a particular instance may not have an immediately perceptible effect upon the flow of the whole stream of commerce. As the court said in the Shore Case, ‘Many small stoppages will have such effect.’ ” Douglas v. Internation*168al Brotherhood of Electrical Workers Union, supra [D.C., 136 F.Supp. 73].
This is not a case where the Federal Board has refused to accept jurisdiction upon the ground that the issue presented does not sufficiently affect the national welfare, e. g., Garmon v. San Diego Building Trades Council, 45 Cal.2d 657, 291 P.2d 1. This is a case where appellees have never sought to invoke the jurisdiction of the National Labor Relations Board and is controlled by the decisions in Garner v. Teamsters, Chauffeurs, and Helpers Local No. 776, 346 U.S. 485, 74 S.Ct. 161, 98 L. Ed. 228; Building Trades Council v. Kinard Construction Co., 346 U.S. 933, 74 S.Ct. 373, 98 L.Ed. 423; Weber v. AnheuserBusch, Inc., 348 U.S. 468, 75 S.Ct. 480, 99 L.Ed. 546; Local Union No. 25 of International Brotherhood of Teamsters, etc. v. New York, N. H. & H. R. Co., 350 U.S. 155, 76 S.Ct. 227, 100 L.Ed. 166; see also Browning King Co. of New York v. Local 195, 34 N.J.Super. 13, 111 A.2d 415; Holman v. Industrial Stamping & Manufacturing Co., 344 Mich. 235, 74 N.W.2d 322; Garmon v. San Diego Building Trades Council, supra. It seems to us that the statements of the Supreme Court of the United States that an unfair labor practice within the meaning of the Labor Management Relations Act, 1947, 29 U.S.C.A. § 141 et seq., is within the exclusive primary jurisdiction of the National Labor Relations Board are unequivocal and do not fairly lend themselves to interpretation by other courts. For example:
“* * * ^ state may not enjoin under its own labor statute conduct which has been made an ‘unfair labor practice’ under the federal statutes. Such was the holding in the Garner case [U.S.] supra. The court pointed out that exclusive primary jurisdiction to pass on the union’s picketing is delegated by the Taft-Hartley Act to the National Labor Relations Board. * * * ” Weber v. Anheuser-Busch, supra, 348 U.S. 475, 75 S.Ct. 485. (Italics ours.)
Every tribunal has the power to hear and determine its own jurisdiction, Stoll v. Gottlieb, 305 U.S. 165, 59 S.Ct. 134, 83 L.Ed. 104, and the same power is not to be denied to the National Labor Relations Board.
“ * * * The corporation contends that, since it denies that interstate or foreign commerce is involved and claims that a hearing would subject it to irreparable damage, rights guaranteed by the Federal Constitution will be denied unless it be held that the District Court has jurisdiction to enjoin the holding of a hearing by the Board. So to hold would, as the government insists, in effect substitute the District Court for the Board as the tribunal to hear and determine what *169Congress declared the Board exclusively should hear and determine in the first instance. The contention is at war with the long-settled rule of judicial administration that no one is entitled to judicial relief for a supposed or threatened injury until the prescribed administrative remedy has been exhausted. * * * ” Myers v. Bethlehem Shipbuilding Corp., 303 U.S. 41, 50, 58 S.Ct. 459, 463, 82 L.Ed. 638.
a * * * The same reasoning which prohibits federal courts from intervening in such cases, except by way of review or on application of the federal board, precludes state courts from doing so. * * * ” Garner v. Teamsters, Chauffeurs, and Helpers Local No. 776, supra, 346 U.S. 491, 74 S.Ct. 166.
We fail to see how it can be otherwise, for as the Garner case further points out:
“ * * * Congress evidently considered that centralized administration of specially designed procedures was necessary to obtain uniform application of its substantive rules and to avoid these diversities and conflicts likely to result from a variety of local procedures and attitudes toward labor controversies.” 346 U.S. 485, 490, 74 S.Ct. 161, 166.
But the National Labor Relations Board “need not accept every controversy of which it has jurisdiction” and “By giving the Board discretion to accept or refuse jurisdiction, the legislative purpose must have been to give the state courts jurisdiction when the Board specifically determines that the controversy will not affect the national economy.” Garmon v. San Diego Building Trades Council, supra [45 Cal.2d 657, 291 P.2d 5], We conclude that the only appropriate forum to determine whether the Board will exercise its primary jurisdiction is in that tribunal wherein the discretion lies. As a practical matter we fail to see how it can be otherwise for assuming that it would be possible for the State Court and the Board to agree as to the facts in a particular case, is it possible to say that unanimity of opinion could be obtained as to the legal conclusion that interstate commerce or the national economy is or is not affected thereby.
The jurisdiction of the National Labor Relations Board is in part predicated on 29 U.S.C.A. § 160(a) providing:
“(a) The Board is empowered, as hereinafter provided, to prevent any person from engaging in any unfair labor practice * * * affecting commerce. * * * ”
It is an unfair labor practice for a labor organization or its agent to refuse to bargain collectively with an employer. 29 U.S. C.A. § 158(b, d). In an “industry affecting commerce” the duty to bargain collec*170tively means at least that no party to a contract shall terminate or modify such contract without giving 60 days written notice, and offer to meet and confer on the proposed modification and within 30 days notify the Federal Mediation and Conciliation Service if no agreement has been reached. 29 U.S.C.A. § 158(d) (1-3). United Elec. Radio & Mach. Workers of America (UE), Local 1113 v. National Labor Relations Board, 96 U.S.App.D.C. 46, 223 F.2d 338. Cf. International Union of Operating Engineers, Local No. 181 v. Dahlem Const. Co., 6 Cir., 193 F.2d 470. Here the appellants without any prior notification or offer to meet and confer with the appellees presumptively attempted to unilaterally modify the collective bargaining agreements by advising the appellees as follows:
“Commencing at the start of the first payroll period after June 20, 1954, the fpllowing modifications to the contract are in effect:”.
Because it introduces new working conditions without following the prescribed procedures for bargaining it is in effect a refusal to bargain. United Electrical, Radio & Mach. Workers of America (UE) Amalgamated Local 259 v. Worthington Corp., D.C,, 136 F.Supp. 31. We believe that the attempted modifications of the collective bargaining agreements reasonably brings the controversy within the cited sections and the exclusive primary jurisdiction of the National Labor Relations Board as an unfair labor practice.
As pointed out this is a case where the appellees have never petitioned the Federal Board for its order compelling the appellants to cease and desist from their conduct.2 We are not deciding that the appellants are guilty of unfair labor practices, but only that if appellants did what appellees assert they did then it would constitute an unfair labor practice. We only hold that the National Labor Relations Board has the exclusive jurisdiction in the first instance to determine whether there is- here an unfair labor practice within the meaning of Congress and, if so, whether such practice has resulted in a controversy affecting interstate commerce. To hold otherwise may thwart the purpose of the national policy to obtain uniform application of procedures to avoid conflicts resulting from a variety of local attitudes.
Appellees attempt to sustain the jurisdiction of the state court on the principle that the act enjoined is the breach or the attempt to induce a breach of the collective bargaining agreement and that a breach of contract leading to irreparable *171damage is properly cognizable in a court of equity. We recognize that there are instances where a state court has enjoined a breach of a collective bargaining agreement on the theory that the Labor Management Relations Act did not preempt all violations of law pertaining to recognition and enforcement of collective bargaining agreements. Philadelphia Marine Trade Association v. International Longshoremen’s Ass’n, 382 Pa. 326, 115 A.2d 419, 733, and Sheet Metal Workers Int. Ass’n, Local No. 249 v. E. W. Daniels Plumbing & Heating Co., 223 Ark. 48, 264 S.W.2d 597. But whatever the distinctions which may be drawn between those cases and the instant case we are satisfied to rest our conclusions on the basis that an unfair labor practice does not lose its characterization as such because it occurs in the violation of a written agreement and if the breach of contract also is an unfair labor practice only the National Labor Relations Board has jurisdiction in the first instance. Such breach is incidental to the violation of the public right which when enforced may obviate the necessity of seeking judicial determination of the private right. United Electrical, Radio & Mach. Workers of America v. General Electric Co., 97 U.S.App.D.C. 306, 231 F.2d 259; In re Third Ave. Transit Corp. v. Quill, 2 Cir., 192 F.2d 971; Grimes & Hauer, Inc., v. Pollock, 163 Ohio St. 372, 127 N.E.2d 203, affirming Ohio App., 119 N.E.2d 889, certiorari denied 350 U.S. 900, 76 S.Ct. 178, 100 L.Ed. 781; Bert Manufacturing Co. v. Local 810, Sup., 136 N.Y.S.2d 805; United Electrical, Radio & Mach. Workers of America (UE) Amalgamated Local 259 v. Worthington Corp., supra. Clearly appellees are attempting to by-pass the remedies created for them by Congress, and thus to circumvent its plain mandate that jurisdiction in the first instance of such matter is vested exclusively in the National Labor Relations Board. Cf. Anson v. Hiram Walker & Sons, Inc., 7 Cir., 222 F.2d 100. We think any other holding will prevent the National Labor Relations Board from exercising its jurisdiction completely freed of interference by other tribunals.
The seeming exception to the exclusively primary jurisdiction of the National Labor Relations Board recently recognized in United Automobile, Aircraft & Agr. Implement Workers of America v. Wisconsin Employment Relations Board, 351 U.S. 266, 76 S.Ct. 794, 100 L.Ed. 1162, that the state has the power to enjoin violence in labor disputes even where it constitutes an unfair labor practice does not have significance in this situation where the asserted breaches of contract have not been followed by substantial acts of unlawfulness or have not otherwise led to riotous or tumultuous conduct of sufficient magnitude to imperil the public peace.
Since as pointed out by Section 160(a) the National Labor Relations Board is. em*172powered to prevent any person from engaging in any unfair labor practice affecting commerce, it is our judgment that the injunctions issued pendente lite in this cause must be set aside as to all parties and they are hereby ordered dissolved forthwith and the case remanded for proceedings not inconsistent herewith.
LA PRADE, C. J., and WINDES, J., concur.. On the 12th day of December, 1951, the United Association and its Locals 469 and 741 were certified by the National Labor Relations Board as the ex-elusive representative of all the employees of the Association of Plumbing Contractors and its members for, the purpose of collective bargaining.
. ■ The National Labor Relations Board has ample authority to enforce its orders requiring the parties to bargain collectively. National Labor Relations Board v. Warren Co., 350 U.S. 107, 76 S.Ct. 185, 100 L.Ed. 96.