— A lesbian couple challenging Oklahoma's ban on gay marriages say the U.S. Supreme Court has bolstered their arguments that the state prohibition is unconstitutional.

The high court's decision last month in a gay marriage case “provides clear and explicit guidance for concluding Oklahoma's marriage ban violates both (the couple's) fundamental right to marry, and the exercise of liberties inherent in such fundamental right,” according to a legal brief filed Monday in the case.

The U.S. Supreme Court struck down a federal law barring benefits for same-sex couples, ruling that it violated “basic due process and equal protection principles applicable to the federal government.”

The lawsuit against the Oklahoma ban was filed in federal court in Tulsa in 2004 and has been stalled for more than a year as same-sex marriage cases from other states moved toward consideration by the U.S. Supreme Court.