The National Labor Relations Board petitions for enforcement of an order based on its finding that the Union committed an unfair labor practice (29 U.S.C. §§ 158(b)(1)(A) and (2)) by refusing to refer William Butler to a job at a bargaining unit different from the one in which he had incurred a dues arrearage.

The existence of the unfair labor practice depended upon the Board’s bargaining unit determination. - The Union contends that the bargaining unit issue was neither alleged nor tried during the proceedings, resulting in a due process violation, and that the Board’s determination constituted an abuse of discretion. The Union also contends that the Board abused its discretion by imposing a new back-pay remedy in its order against the Union.

The National Labor Relations Board’s order is enforced. The Union waived any due process contentions it may have had by failing to raise them in its motion for reconsideration. Garment Workers v. Quality Mfg. Co., 420 U.S. 276, 281 n. 3, 95 S.Ct. 972, 975 n. 3, 43 L.Ed.2d 189 (1975). The Board did not abuse its discretion in determining that Butler was refused referral to a different bargaining unit. The Union failed to show that the employer in question unequivocally intended to belong to the multi-employer bargaining unit. See N.L.R.B. v. New York Typographical Union, 632 F.2d 171, 183-84 (2d Cir. 1980).

The Board did not abuse its discretion in awarding the back-pay remedy in the adjudication. Any doubt about the change in the back-pay rule was resolved by this court in Sheet Metal Workers’ Intern. Ass’n v. N.L.R.B., 716 F.2d 1249 (9th Cir. 1983).