Portugal's Parliament approved a gay marriage bill on Thursday, the AP reported. The bill, however, does not include the right to adopt.

Passage of the bill in the Socialist-controlled Parliament was never in doubt, but a presidential veto threatens to prevent the bill from becoming law.

President Anibal Cavaco Silva is a Roman Catholic and a member of the PSD Party, groups which oppose the legalization of gay marriage, and he has publicly stated his opposition to the bill. The president has 20 days to reject the bill.

Socialists and their allied parties, however, say they have the votes to override a presidential veto.

Last July, Portugal's Constitutional Court upheld the constitutionality of a gay marriage ban, denying a lesbian couple the right to marry. In a 3 to 2 decision, the court said that while the Constitution outlaws discrimination based on sexual orientation, it does not say gay marriage must be permitted.

After the loss, Prime Minister Jose Socrates, who heads the Socialist Party, pledged to introduce a gay marriage bill if returned to power in the general election.

It's possible President Silva could forward the issue to the Constitutional Court, commentators have speculated in the Portuguese press.

The Vatican condemned the legalization of gay marriage in neighboring Spain in 2005 and has called for the ouster of Socialists in the country, but opposition in Portugal has been muted.

Gay marriage is legal in five European counties, including Spain, Belgium, the Netherlands, Norway and, most recently, Sweden.