Any provision of a hiring hall contract or agreement which obligates a contractor to hire, if available, only employees referred to the contractor by a labor organization shall be void as against public policy and unenforceable with respect to employment under any public works contract unless at the date of execution of the hiring hall contract or agreement, or within thirty days thereafter, the labor organization has in effect procedures for referring qualified employees for hire without regard to race, color, religion, national origin, military status as defined in section 4112.01 of the Revised Code, or ancestry and unless the labor organization includes in its apprentice and journeyperson’s membership, or otherwise has available for job referral without discrimination, qualified employees, both whites and non-whites (including African-Americans).