WASHINGTON - The City Council voted yesterday to legalize gay marriage, giving supporters a victory after a string of recent defeats elsewhere and sending the issue to Congress, which has final say over laws in the nation's capital.

Mayor Adrian Fenty has promised to sign the bill, which passed 11-2, and gay couples could begin marrying as early as March if Congress allows it to become law. Democratic congressional leaders have suggested they are reluctant to get involved, though gay- marriage opponents say they will try to get it overturned either in Congress or at the polls.

The bill had overwhelming support among council members and its passage was no surprise. Two members voted "I do" when their names came up, and when the vote finished a packed chamber erupted into cheers and clapping.

"Make no mistake, 2009 has been one hell of a year for marriage equality," said David Catania, who introduced the bill and is one of two openly gay council members.

The "no" votes included former mayor Marion Barry, now a council member, who voted, "I don't."

If the bill becomes law, the district will join Connecticut, Iowa, Massachusetts and Vermont in issuing marriage licenses to same-sex couples. They will be able to wed in New Hampshire starting in January.