Opponents of a District of Columbia gay marriage law widely expected to take effect in March have lost their lawsuit against the city's elections board, the Washington Post reported.

Stand for Marriage DC challenged a District of Columbia Board of Elections and Ethics ruling that blocked opponents from pursuing a ballot initiative banning gay marriage in the District. The board concluded twice that such a measure would violate the city's Human Rights Act that prohibits discrimination based on sexual orientation.

On Thursday, D.C. Superior Court Judge Judith N. Macaluso agreed with the city, saying the board “properly rejected the proposed initiative” because of the Human Rights Act.

Thirty-nine Republican members of Congress, including two senators, James M. Inhofe of Oklahoma and Roger Wicker of Mississippi, and 37 House members, had filed an amicus brief in support of gay marriage opponents.

“As members of the District's ultimate legislative body, amici are concerned about the extent of the District's delegated legislative authority, the preservation of Congress' constitutional authority, and the interpretation of home rule,” the brief says.

Bishop Harry Jackson, a minister at the Hope Christian Church in Beltsville, Maryland, formed Stand for Marriage DC in the spring of 2009 after lawmakers approved a gay marriage-recognition bill and promised to legalize gay marriage in the city.

Jackson and his supporters could appeal the ruling to an appellate court, but most likely not before the gay marriage law – approved by lawmakers on December 15 – goes into effect. Congress, which has final say on laws approved by the city, has 30 legislative days to reject the measure. City officials say they expect the law to go into effect on March 2, but because of a 3-day waiting period, the District will not see its first gay wedding until March 5, at the earliest.