Sacramento - Governor Arnold Schwarzenegger has vetoed a bill that would have made California the second state in the nation to legalize same-sex marriage.

Schwarzenegger ran as a Republican who would be conservative on business and economics, but liberal on issues like abortion and gay marriage.

But now, he has single-handedly stopped California's legislature from legalizing gay marriage.

He vetoed the bill that would have changed the definition of marriage to say that it was the union of two persons rather than a union of a man and a woman.

Schwarzenegger said that the people of California voted in the year 2000 to make only marriage between a man and a woman valid, and the legislature could not override the will of the people.

He also pointed out a state appeals court is deciding now whether that vote in 2000 was constitutional, and its likely the California Supreme Court will ultimately decide the issue.

The governor is taking heat from gay rights groups over his veto decision. But he says he is in favor of California's domestic partner laws, which basically grant most of the same rights and obligations of marriage to gay couples.

Randy Thomasson, one of California's leading opponents of gay marriage, said Schwarzenegger's done the right thing.

The bill would have made California the second state to legalize same-sex marriage.