Washington D.C. Councilman David Catania (I-At Large) introduced his gay marriage bill Tuesday.

Supporters of gay marriage in the District have been expecting the legislation since July, when lawmakers agreed to recognize gay marriages performed outside the District, effectively allowing gay and lesbian couples to marry so long as they hop on a train to a nearby state where gay marriage is legal.

The bill, titled the Religious Freedom and Civil Marriage Amendment Act of 2009, would change the definition of marriage to say that “marriage is the legally recognized union of two people” and “any person who otherwise meets the eligibility requirements … may marry any other eligible person regardless of gender.”

Four states – Connecticut, Iowa, Vermont and Massachusetts – allow gay marriage. New Hampshire will begin in January. Lawmakers in Maine also approved a gay marriage law in the spring, but opponents have managed to put the law up for a vote. Question 1 will decide whether the law remains.

Catania introduced his bill at a standing-room-only council meeting, the Wall Street Journal reported.

“There is no question that we are about to embark on an exciting journey here in the district,” he said.

With 10 out of 13 council members supporting the bill, its passage is nearly certain. But it might get a fight from Congress, which has the final say on laws passed by the city.

Utah Representative Jason Chaffetz is already on record opposing the bill.

“Some fights are worth fighting for,” the Republican told the paper.

But Catania, one of two openly gay council members, says he has spoken with the White House about the issue.

“We are not asking the White House to change its position on marriage equality – the discussion with the White House is about supporting local home rule,” Catania told reporters. “Everyone knows where the president is on this issue, but we also know the president has high regard for home rule and local autonomy. And on those grounds we believe the White House should work with us in defending the actions of the local government.”

Any resolution that would block D.C.'s gay marriage law would need to be signed by President Obama.

The measure is more likely to encounter turbulence from the small but vocal group of religious leaders who attempted to end the city's gay marriage recognition law.

Opponents – lead by Bishop Harry Jackson, senior pastor of Hope Christian Church and founder of the anti-gay marriage group Stand4MarriageDC – continue to pursue a ballot initiative that would ban gay marriage in the District. The one sentence initiative says, “Only marriage between a man and a woman is valid and recognized in the District of Columbia.”

Catania said he hopes for a vote in December.