The French Senate voted today to legalise same-sex marriage in France, putting a landmark bill on track to become law by summer.

The vote in the upper house of Parliament - led by President Francois Hollande's Socialists - comes despite boisterous protests. Opponents, mostly conservatives and Roman Catholics, have sought to defend traditional marriage.

France's justice minister, one of the bill's loudest supporters, said the reform recognises that many children are already living with same-sex parents and deserve the same protections afforded children of opposite-sex parents.

"These are children that scrape their knees, eat too much sweets, don't like broccoli, drive you crazy... we protect them," Christine Taubira told senators following the vote.

The justice minister said the reform will "move our institutions towards ever more freedom, equality and personal respect".

Both houses of Parliament will now take up a second reading to consider minor Senate changes to the bill passed in February by the National Assembly, also controlled by a Socialist-led majority.

Some conservative senators vowed to continue their opposition to the bill.

"The parliamentary process continues so we will keep talking with the French people who seem to change their position," said UMP party senator Jean-Pierre Raffarin. "So nothing is definitive and the debate continues."

Polls have shown a narrow majority of French support legalising gay marriage, though that support falls when questions about adoption and conception of children come into play.

The bill would allow gay marriage and let same-sex couples adopt children. On the campaign trail last year, Mr Hollande pledged to push through such legislation if elected.

About a dozen mostly European nations already allow gay marriage.

Opponents and supporters of the bill have staged loud demonstrations throughout the bill's passage through Parliament. In mid-January, at least 340,000 people swarmed on the Eiffel Tower to protest against the plan to legalise gay marriage, according to police estimates. Two weeks later, about 125,000 proponents of the bill marched in the capital.

French civil unions, allowed since 1999, are at least as popular among heterosexuals as among gay and lesbian couples. But that law has no provisions for adoption or assisted reproduction.