SACRAMENTO, CALIF. ? Gov. Arnold Schwarzenegger announced Wednesday he will veto a bill that would have made California the first state to legalize same-sex marriage through its elected lawmakers.

Schwarzenegger said the legislation, given final approval Tuesday by lawmakers, would conflict with the intent of voters when they approved an initiative five years ago. Proposition 22 was placed on the ballot to prevent California from recognizing same-sex marriages performed in other states or countries.

“We cannot have a system where the people vote and the Legislature derails that vote,” the governor’s press secretary, Margita Thompson, said in a statement.

“Out of respect for the will of the people, the governor will veto (the bill).”

Proposition 22 stated that “only marriage between a man and a woman is valid or recognized in California.” The bill to be vetoed by Schwarzenegger would have defined marriage as a civil contract between “two persons.”

In Massachusetts, recognition of gay marriages came through a court ruling.

Gay rights advocates accused Schwarzenegger of betraying the bipartisan ideals that helped get him elected in the 2003 recall.

“Clearly he’s pandering to an extreme right wing, which was not how he got elected,” said Geoff Kors, executive director of Equality California, one of the bill’s sponsors. “He got elected with record numbers of lesbian and gay voters who had not previously voted for a Republican, and he sold us out.”

Kate Kendell, executive director of the National Center for Lesbian Rights, said she was not surprised by word of Schwarzenegger’s pending veto.

“Any girlie man could have vetoed this legislation,” she said, referring to a term Schwarzenegger used previously to mock Democratic legislators. “A real man demonstrating real leadership as governor of the most populous state in the nation would have chosen a different course of action.”

The governor has until Oct. 9 to issue the veto.

Despite his promise to do so, Schwarzenegger “believes gay couples are entitled to full protection under the law and should not be discriminated against based upon their relationship,” Thompson’s statement said. “He is proud that California provides the most rigorous protections in the nation for domestic partners.”

The Republican governor had indicated previously that he would veto the bill, saying the debate over same-sex marriage should be decided by voters or the courts.

A state appeals court is considering appeals of a lower court ruling earlier this year that overturned Proposition 22 and a 1978 law that first formally defined marriage as a union between a man and a woman. Meanwhile, opponents of same-sex marriages are planning measures on the ballot next year that would place a ban on gay marriages in the state Constitution.