Washington State Governor Chris Gregoire on Monday will sign a gay marriage bill approved by lawmakers, the AP reported.

Gregoire will sign the bill into law at 11:30AM, making Washington the seventh state to legalize gay marriage.

The Democrat-controlled House approved the measure with a 55-43 vote on Wednesday, a day after a federal court declared California's gay marriage ban, Proposition 8, in violation of the United States Constitution, and one week after the Washington Senate passed the measure with a wider margin than expected.

Gregoire for the first time endorsed marriage equality at a press conference introducing the bill last month.

In an interview with gay glossy The Advocate, the governor said she struggled with her Catholic faith on the issue.

“I think it's fundamentally wrong to discriminate. At the same time, I have accepted my religion can have religious freedom to do what it chooses to do, but that cannot allow a state to engage in discrimination, so that's been my evolution,” she said.

(Related: Chris Gregoire urges Americans to support gay marriage.)

Opponents have already begun an effort to repeal the measure at the ballot box. But voters in 2009 rejected a ballot question aimed at repealing the state's domestic partnership law, which gives gay and lesbian couples all the protections of marriage without the name.

If opponents gather sufficient signatures to put the law up for a vote, its June start would be put on hold pending the outcome of a November election.