NLRB v. Great Dane Trailers

In NLRB v. Great Dane Trailers (1967) 388 U.S. 26, the Supreme Court held that although there was no proof of antiunion bias, the employer's act of refusing to pay accrued vacation benefits to striking employees under a terminated collective bargaining agreement while promising to pay such benefits to nonstrikers and strike replacements was inherently destructive of important employee rights under NLRA section 8(a)(3) and constituted an unfair labor practice. The court announced certain rules for finding an unfair labor practice based on discrimination in term or condition of employment: a finding of unfair labor practice normally turns on whether discriminatory conduct was motivated by an antiunion purpose. Proof of such employer motivation may make unlawful employer conduct which in other circumstances would have been perfectly lawful.