Gregoire set to sign bill legalizing gay marriage in Wash.

OLYMPIA, Wash. -- Gov. Chris Gregoire will sign a measure legalizing gay marriage in Washington state into law on Monday, but opponents have promised to fight back with a ballot measure that would allow voters to overturn it.

The House passed the bill on a 55-43 vote last Wednesday, a week after the Senate approved it. Gregoire will sign the bill in the state reception room in the Capitol at 11:30 a.m.

The law takes effect June 7, but if opponents gather enough signatures to take their fight to the ballot, the law will put on hold pending the outcome of a November election.

They must turn in more than 120,000 signatures by June 6 to challenge the proposed law. An anti-gay marriage initiative has also been filed. To qualify, 241,153 signatures must be submitted by July 6.

Washington state's momentum for same-sex marriage has been building and the debate has changed significantly since 1998, when lawmakers passed Washington's ban on 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.

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

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.