WASHINGTON - A measure to let voters decide whether to ban same-sex marriages in D.C. cannot go on the ballot because it would violate a city human rights law, the Board of Elections and Ethics ruled Tuesday.

The D.C. City Council is expected to approve homosexual marriage next month, but opponents wanted voters to weigh in.

The elections board said allowing residents to vote on a ban would conflict with the city's 1977 Human Rights Act, which prohibits discrimination.

Errol R. Arthur, chairman of the two-member board, suggested as much at an October hearing. He said in a press release Tuesday that the "laws of the District of Columbia preclude us from allowing this initiative to move forward"...