OLYMPIA, Wash (Reuters) - The Washington state Senate was expected to endorse legalization of gay marriage Wednesday night in a vote that would move the state a step closer to becoming the nation's seventh to recognize same-sex unions.
The vote, scheduled to start following a floor debate, is considered pivotal given that gay rights advocates have previously failed to muster sufficient support in the state Senate to ensure passage.
The political dynamic shifted after Governor Christine Gregoire, a Democrat in her final year in office, announced last month she was backing the gay marriage bill.
Democratic Senator Ed Murray, its chief sponsor, said last week proponents had secured the 25 votes needed for a simple majority in the 49-seat chamber. Murray has said he hoped to end up with 27 or more votes, though the controversial issue was likely to result in a lengthy floor debate that could last well into the night.
With passage in the state House of Representatives already seen as virtually assured, opponents of same-sex matrimony say they will seek the measure's repeal with a referendum asking voters to reaffirm marriage as being exclusively between one man and one woman.
To qualify for the November ballot, they need to collect at least 120,577 signatures of registered voters by July 6.
Six other states recognize same-sex marriage -- New York, Massachusetts, Connecticut, Vermont, New Hampshire and Iowa -- as does the District of Columbia. Supporters are moving to pass similar statutes in Maryland and New Jersey.
A referendum to legalize gay marriage in Maine has qualified for the November ballot there.
Washington state's lower House could vote on gay marriage as early as February 8. Should it reach the governor's desk, Gregoire plans to sign the measure, barring any drastic changes made during the rest of the legislative session, which ends March 8, a representative of the governor said.
Both House and Senate versions of the bill include language to allow gay couples from out of state to get married in Washington. They both include an amendment allowing religious organizations to refuse to rent out their chapels or other facilities as venues for same-sex weddings.
The legislation was moving faster than originally anticipated, said Representative Jamie Pedersen, the bill's prime sponsor in the House.
"The groundswell of support ... was much better than what we could have hoped for," Pedersen said. "Big controversial things usually get resolved in the last days of session, so this is somewhat unusual."
Opponents point out that voters have yet to approve gay marriage in any state referendum and have in some instances overturned same-sex marriage laws enacted by legislators or the courts. Gay marriage remains outlawed in more than 40 states.
Oregon voters passed a law upholding traditional marriage in 2004, voiding same-sex weddings that some counties had performed earlier that year. California voters in 2008 approved a state constitutional amendment banning gay marriage. That measure is under challenge in federal court.
Several prominent Pacific Northwest companies, including Microsoft, Starbucks and Nike, have endorsed Washington's legislation.
On the other side, the state's Catholic bishops and other religious conservatives are amassing thousands of Washingtonians against the legislation, including voters who supported the state's expansion of domestic-partnership benefits in recent years but draw the line at marriage.
Editing by Steve Gorman, Daniel Trotta and Cynthia Johnston