Opening arguments from Montana's attorney general are due Feb. 27 in his appeal of a federal court order that struck down the state's gay marriage ban.

Attorney General Tim Fox has said it's his sworn duty to uphold Montana's Constitution, which voters amended in 2004 with a definition of marriage as between a man and a woman.

U.S. District Judge Brian Morris ruled Wednesday that the amendment violated the guarantee of equal protection for all citizens under the U.S. Constitution.

Arguments from plaintiffs represented by the ACLU of Montana are due March 30.

The case is before the 9th U.S. Circuit Court of Appeals.