Washington state lawmakers voted to approve gay marriage Wednesday, setting the stage for the state to become the seventh in the nation to allow same-sex couples to wed.

The action comes a day after a federal appeals court declared California's ban on gay marriage unconstitutional, saying it was a violation of the civil rights of gay and lesbian couples.

The Washington House passed the bill on a 55-43 vote. The state Senate approved the measure last week. And Democratic Gov. Chris Gregoire is expected to sign the measure into law next week.

However, gay couples can't begin walking down the aisle just yet.

The proposal would take effect 90 days after the governor signs, but opponents have promised to fight gay marriage with a ballot measure that would allow voters to overturn the legislative approval.

If opponents gather enough signatures to take their fight to the ballot box, the law would be put on hold pending the outcome of a November election.

Otherwise gay couples could wed starting in June.

Washington state has had domestic partnership laws since 2007, and more than a dozen other states have provisions, ranging from civil unions to gay marriage, supporting same-sex couples.

Gay marriage is legal in New York, Connecticut, Iowa, Massachusetts, New Hampshire, Vermont and Washington D.C.

Lawmakers in New Jersey are expected to vote on gay marriage next week, and Maine could see a gay marriage proposal on the November ballot.

Proposed amendments to ban gay marriage will be on the ballots in North Carolina in May and in Minnesota in November.

The San Francisco-based 9th U.S. Circuit Court of Appeals on Tuesday ruled against California's voter-approved same-sex marriage ban, known as Proposition 8.

The three-judge panel gave gay marriage opponents time to appeal the 2-1 decision before ordering the state to allow same-sex weddings to resume. The judges also said the decision only applies to California, even though the court has jurisdiction in nine western states.

Lawyers for the coalition of conservative religious groups that sponsored Proposition 8 said they have not decided if they will seek a new 9th Circuit hearing or file an appeal directly to the U.S. Supreme Court.

Washington state's momentum for same-sex marriage has been building and the debate has changed significantly since 1998, when lawmakers passed Washington's Defense of Marriage Act banning gay marriage. The constitutionality of that law ultimately was upheld by the state Supreme Court in 2006. But earlier that year, a gay civil rights measure passed after nearly 30 years of failure, signaling a change in the Legislature.

The quick progression of domestic partnership laws in the state came soon after, with a domestic partnership law in 2007, and two years of expansion that culminated in 2009 with "everything but marriage" expansion that was upheld by voters.

In October, a University of Washington poll found that an increasing number of people in the state support same-sex marriage. About 43 percent of respondents said they support gay marriage, up from 30 percent in the same poll five years earlier. Another 22 percent said they support giving identical rights to gay couples, without calling the unions "marriage."

If a challenge to gay marriage law was on the ballot, 55 percent said they would vote to uphold the law. And 38 percent said they would vote to reject a gay marriage law.

The gay marriage bill also has the backing of several prominent Pacific Northwest businesses, including Microsoft, Nike and Starbucks.