Three newly filed legal challenges accuse gambling regulators of overstepping their authority with proposed rules that would prohibit obstacles on horse tracks, force jockeys to wear white pants and protective equipment such as helmets and require jai alai frontons to be covered.

The challenges, filed with the state Division of Administrative Hearings on July 30, are the latest twist in a prolonged effort by the Department of Business and Professional Regulation to create new rules, many of them focused on controversial barrel racing, for the pari-mutuel industry.