DENVER (AP) — A Colorado baker who refused to make a wedding cake for a gay couple on religious grounds — a stance partially upheld by the U.S. Supreme Court — has sued the state over its opposition to his refusal to bake a cake celebrating a gender transition, his attorneys said Wednesday.

Jack Phillips, owner of the Masterpiece Cakeshop in suburban Denver, claimed that Colorado officials are on a "crusade to crush" him and force him into mediation over the gender transition cake because of his religious beliefs, according to a federal lawsuit filed Tuesday.

Phillips is seeking to overturn a...