A group of 212 mostly Democratic members of Congress filed a brief Friday urging the U.S. Supreme Court to overturn the 1996 federal law recognizing marriage as a union between members of the opposite sex.

Justices will take up the constitutionality of the Defense of Marriage Act in late March and also review California’s Proposition 8, a 2008 measure that amended the state’s constitution to narrow the definition of marriage as between opposite-sex couples.

The 1996 law recognizes only heterosexual marriages for federal and interstate purposes such as income taxes and health insurance.

Republican leadership, using the Bipartisan Legal Advisory Group in the House, began defending the statute in courts after the Obama administration said in 2011 it would no longer do so.

The lawmakers’ brief states that the law “imposes a sweeping and unjustifiable federal disability on married same-sex couples.”

The move by members follows a brief filed Thursday by the Obama administration that also urges the court to overturn Proposition 8.

President Barack Obama was asked about the decision and his evolution on the issue at a briefing with reporters Friday.

“We cannot discriminate against same-sex couples when it comes to marriage,” Obama said.

Congressional Democrats and Republicans have long clashed over the 1996 federal DOMA law, but both sides agree that the high court should step in. For Democrats, it is a matter of doing away with a statute that they say violates equal protection guarantees by withholding federal benefits from same-sex couples who were legally married under state law. Several federal appeals courts have agreed.

For Republicans, the law serves a legitimate governmental interest by promoting the traditional definition of marriage and encouraging family values, such as child-rearing with both a mother and a father.

In a filing at the Supreme Court in June, lawyers for House Republicans made clear that they prefer a swift resolution to the legal debate, particularly as challenges over the marriage law have emerged in more courts.

The brief submitted Friday is signed by Democratic lawmakers and independents including Sen. Angus King of Maine and Bernard Sanders of Vermont, who caucus with Democrats. No Republicans signed it.