under a labor contractor, in any case where such labor contractor or labor subcontractor is responsible for the rights and protections of this Act with respect to the employee. . (2) Unfair labor practice Section 8(a) of the National Labor Relations Act ( 29 U.S.C. 158(a) ), as amended by section 102(b)(3)(B), is further amended by adding at the end the following: (8) to reject contractors in whole or in part because the contractors have workforces represented by labor organizations, including— (A) when the employer initially solicits bids for a contract for an as-yet-unchosen contractor to provide a good or service to the employer, by rejecting any contractor in whole or in part because the contractor's workforce is represented by a labor organization