Updated

The Supreme Court is expected to hear arguments in late March for two prominent cases that could test the bounds of laws restricting gay marriage, Fox News has learned.

The first case will be argued March 26, involving a dispute over California's constitutional ban on gay marriage known as Proposition 8. The 9th U.S. Circuit Court of Appeals earlier struck down that rule.

The second case is expected to be argued the following day, on a challenge to part of the federal Defense of Marriage Act.

The law was passed in 1996 by overwhelming bipartisan majorities in the House and Senate and signed by President Bill Clinton. It defines marriage for all purposes under federal law as between a man and a woman and has been used to justify excluding gay couples from a wide range of benefits that are available to heterosexual couples.

Four federal district courts and two courts of appeal have overturned the provision in various cases on grounds that it unfairly deprives same-sex couples of federal benefits. The Obama administration broke with its predecessors when it announced last year that it no longer would defend the provision.

Republicans in the House of Representatives stepped in to take up the defense of the law in court.

The Prop 8 case, though, could have the broadest implications.

A decision in favor of gay marriage could set a national rule and overturn every state constitutional provision and law banning same-sex marriages. A ruling that upholds California's ban would be a setback for gay marriage proponents in the nation's largest state, although it would leave open the state-by-state effort to allow gays and lesbians to marry.

Gay marriage is legal in nine states and the District of Columbia.

Fox News' Shannon Bream and The Associated Press contributed to this report.