Texas Government Code - GOV'T § 617.002. Collective Bargaining by Public Employees Prohibited

(a) An official of the state or of a political subdivision of the state may not enter into a collective bargaining contract with a labor organization regarding wages, hours, or conditions of employment of public employees.

(b) A contract entered into in violation of Subsection (a) is void.

(c) An official of the state or of a political subdivision of the state may not recognize a labor organization as the bargaining agent for a group of public employees.