Code of Alabama
Chapter 8 - Fair and Open Competition in Governmental Construction Act.
Section 39-8-4 - Certain Contract Terms Prohibited.

A public agency awarding any contract for the construction, repair, remodeling, or demolition of a public improvement, or obligating funds pursuant to such a contract, shall ensure that neither the awarding public agency nor any construction manager acting on behalf of the public agency, in its bid specifications, project agreements, or other controlling documents shall include any of the following:
(1) A term that requires, prohibits, encourages, or discourages bidders, contractors, or subcontractors from entering into or adhering to agreements with a collective bargaining organization relating to the construction project or other related construction projects.
(2) A term that discriminates against bidders, contractors, or subcontractors based on the status as a party or nonparty to, or the willingness or refusal to enter into, an agreement with a collective bargaining organization relating to the construction project or other related construction projects.