Gov. Arnold Schwarzenegger (search) followed through Thursday on his promise to veto a bill to legalize same-sex marriage (search), leaving the issue up to voters or judges who will likely face the volatile issue in the next year.

"This bill simply adds confusion to a constitutional issue," he said in a veto message.

Schwarzenegger vowed to veto the bill Sept. 7, a day after the legislature became the first in the country to approve a bill allowing gays and lesbians to wed.

Click here to read the text of the Calif. Same-Sex Marriage Bill (FindLaw).

Schwarzenegger said the bill by Assemblyman Mark Leno, D-San Francisco, contradicted Proposition 22 (search), which was approved by voters in 2000 and said only a marriage between a man and woman is valid.

The governor said the state Constitution barred the Legislature from enacting a law allowing gay marriage without another vote of the people and Leno's bill wouldn't provide for that vote.

Schwarzenegger noted that a state appeals court was considering whether the state's ban on gay marriage was constitutional and that the issue would likely be decided by the California Supreme Court.

"If the ban of same-sex marriage is unconstitutional this bill is not necessary," he said. "If the ban is constitutional this bill is ineffective."

Leno, who is one of six openly gay state lawmakers, said Schwarzenegger had missed a historic opportunity to stand up for civil rights.

"He cannot claim to support fair and equal legal protection for same-sex couples and veto the very bill that would have provided it to them," said Leno. "Words are cheap. We're looking for action. We're looking for leadership."

In his veto message, Schwarzenegger said he supported the state's domestic partner laws, which give same-sex couples most of the rights and obligations of married couples, and would oppose efforts to overturn or weaken those statutes.

"I believe that lesbian and gay couples are entitled to full protection under the law and should not be discriminated against based on their relationships," he said.

Leno's bill was approved by bare majorities in the state Assembly and Senate. It would take two-thirds votes in both houses to overturn the veto and there hasn't been a veto override in California in more than 20 years.

Eddie Gutierrez, a spokesman for Equality California, a gay rights group that supported the bill, said Schwarzenegger had merely delayed the day when gay marriage is legal.

"We are extremely disappointed with the governor's decision," he said. "By denying us marriage equality he has turned a back to our community."

Randy Thomasson, president of the Campaign for California Families, a group that opposed the bill, said Schwarzenegger had done the right thing.

But he said voters should approve an initiative next year that would put a ban on same-sex marriages in the state Constitution.