Thousands of opponents of gay marriage took to the streets of Paris on Sunday to defend their vision of family values, hoping to revive the issue in political debates ahead of next year's presidential election.
About 24,000 people took part in the demonstration, police said, far fewer than the several hundreds of thousands the group "Demo for All" mobilized in 2012 and 2013 in an unexpectedly strong show of opposition from conservatives, especially Roman Catholics.
The Socialist government legalized same-sex marriage, which it called "Marriage for All", in 2013.
Police said 13 people were arrested after a scuffle at the protest, including six topless women from the activist group Femen. Some of them had words "Hate is not a family value" scrawled on their chests.
Organizers of Sunday's protest aim to pressure politicians on the right, who face a presidential primary next month, to agree to repeal the law if they are elected president.
The protesters marched through prosperous western sections of Paris, waving French flags and the "Demo for All" movement's blue and pink colors. Some held signs declaring "All together for the family" and "In 2017, I'll vote for the family."
Organizers estimated the turnout at 200,000.
"Even if the gay marriage law has been adopted, we will continue the protest to show that it is not good and we want it to be repealed. We want to influence the political debate that will take place in the coming months," said one protester.
Opinion polls show that a majority in France do not want the gay marriage law to be repealed.
Demonstrators also spoke out against surrogate motherhood, which gay couples could use to create a family.
Same-sex marriage proponents pushed for surrogacy to also be allowed in the 2013 law, but the government decided not to revoke the current ban after seeing the unexpected protests that "Demo for All" staged during the heated debate over the reform.
Former President Nicolas Sarkozy, who is trailing rival Alain Juppe in the race to head the conservative Republicans party ticket in 2017 election, said on Sunday he would not repeal same-sex marriage if he were returned to the Elysee Palace.
"I believe France has many other important issues to deal with such as security, terrorism and unemployment, rather than recreate conditions for another hysterical debate," Sarkozy said during a political discussion show.