A coalition of gay and lesbian rights groups are urging President Obama to turn down defending the Defense of Marriage Act (DOMA).

Massachusetts-based gay rights group Equal Rep is spearheading the effort that asks Obama to keep his promise to overturn DOMA by not defending an upcoming legal challenge to the law.

Gay & Lesbian Advocates & Defenders (GLAD), the Boston-based gay rights advocacy group at the center of the gay marriage debate in New England, filed a lawsuit on behalf of eight gay married couples and three surviving spouses from Massachusetts in April. They claim the federal DOMA discriminates against gay couples and is unconstitutional.

The lawsuit challenges a narrow portion of the act that defines marriage as a heterosexual union for federal agencies. Victory would not alter marriage laws in any states, but would allow gay couples married in states where gay marriage is legal to access federal benefits currently being denied.

The U.S. Department of Justice is responsible for defending laws enacted by Congress and has until the week of June 22 to file a response to the lawsuit.

The Operation Flip Flop campaign asks supporters to lobby the president to instruct the Department of Justice not to defend the law in court.

“President Obama, the defense of this discriminatory and archaic law will be tantamount to nothing short of a flip flop from your previously stated intentions,” said Equal Rep Founder Paul Sousa in a statement.

Meanwhile, momentum for repeal of DOMA is building.

Saturday, Representative John Conyers, a Michigan Democrat, signaled that a bill that would repeal DOMA, including sections that allow states to ignore legal gay marriage, is ready to be voted out of the House Judiciary Committee he chairs.

“Well, in my committee, yes, but in the House and Senate, that's a different question,” Conyers told the Michigan Messenger about a DOMA repeal passing.

California lawmakers are preparing a joint resolution that supports that effort. Assemblymember Julia Brownley, a Democrat from Santa Monica, has introduced a resolution sponsored by Equality California (EQCA) that would put the state of California on record in support of an immediate repeal of DOMA.

“If a state recognizes the love and commitment of one couple, the federal government must do the same,” said Assemblymember Brownley in introducing the bill. “I urge Congress and the president to take a stand on the side of liberty and treat all Americans equally.”

And late last year, former Georgia Congressman Bob Barr, the author of the law, wrote “It truly is time to get the federal government out of the marriage business” in calling for repeal.