HELENA — Four couples challenging Montana's ban on gay marriages have asked a federal judge to decide the issue without going to trial.

The couples, represented by the American Civil Liberties Union, filed the request Wednesday.

ACLU Montana legal director Jim Taylor said the 9th U.S. Circuit Court of Appeals' recent decision to strike down similar bans in Idaho and Nevada should convince U.S. District Judge Brian Morris to rule in their favor.

Montana is part of the 9th Circuit, and district judges use decisions from the appellate court as precedents for their rulings.

Voters approved the ban in 2004 as an amendment to Montana's constitution. The couples challenging the ban say it unconstitutionally denies them equal protection and due process.