Passage of a gay marriage bill in Washington state remains 4 votes shy of passage, but 7 lawmakers say they remain undecided.

According to a tally by The Associated Press, the measure has sufficient support to clear the House, but a 21 to 18 count leaves it 4 votes shy in the Senate, where 25 votes are needed for passage.

Governor Chris Gregoire, who previously signed bills expanding the state's current domestic partnership law, last week publicly endorsed marriage equality for the first time.

Five Democratic and two freshman Republican senators say they remain undecided.

Democratic Senators Karen Fraser of Olympia and Rosemary McAuliffe of Bothell have signaled they would likely favor the measure but were unwilling to commit.

Republican Senators Joe Fain of Auburn and Andy Hill of Redmond are also leaning in favor of the measure.

Senator Ed Murray of Seattle, a Democratic leader on the issue of gay marriage, said that he's “50 percent optimistic” it will pass.

“I can't declare victory,” he said. “I don't think we'll know we have the votes until we actually vote.”

Two Republican lawmakers are among the “yes” votes: Senators Steve Litzow of Mercer Island and Cheryl Pflug of Maple Valley.

“I don't feel diminished when another human being is allowed to exercise the same rights that I enjoy,” Pflug said. “I would feel diminished if I voted to deny others the right to exercise those same rights and freedoms.”