Local Government Code §143.363

(a) For the purpose of any disciplinary appeal to either the civil service commission or a hearing examiner, all police officers have the right to choose to be represented by any person of their choice or by the police employee group selected as the bargaining agent. (b) An agreement may not interfere with the right of a member of a police employee group to pursue allegations of discrimination based on race, creed, color, national origin, religion, age, sex, or disability with the Commission on Human Rights or the Equal Employment Opportunity Commission or to pursue affirmative action litigation.