OLYMPIA, Wash. (AP) - Voters may be presented with two ballot measures seeking to overturn a recently passed measure that would legalize same-sex marriage in Washington state.

On Wednesday, the Legislature approved a gay marriage bill with a 55-43 vote in the House. The Senate approved it last week on a 28-21 vote, and now the bill awaits a signature from Gov. Chris Gregoire. She is expected to sign the measure into law next week.

Opponents have already promised to challenge the measure at the ballot with a referendum, which would ask voters whether they want to uphold the law or overturn it. But another gay marriage opponent, Everett attorney Stephen Pidgeon, had already filed an initiative last month seeking to change the current state statute, which says that marriage is a civil contract between a male and a female. Pidgeon wants it to be changed to "between one man and one woman."

He said the clarification is necessary because he is concerned legalizing same sex marriage "will lead to the liberalization of marriage laws to allow for polygamy and other forms of relationships."

Pidgeon said that he is carrying on with his initiative effort in spite of other groups' decision to move forward with a referendum. To qualify for the November ballot, Pidgeon must submit at least 241,153 signatures of valid registered voters by July 6.

An official organization supporting the referendum has not yet formed, but several groups involved with the referendum attempt said an announcement is likely next week. To qualify the referendum for the ballot, more than 120,000 signatures must be submitted by June 6.

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