Organisers of a Paris protest against gay marriage say more than one million people have taken part in the event to express anger at the bill passed into law last week.
Similar demonstrations failed to stop the law – which also allows gay people to adopt.
“Because the law has been passed, we should be silent? We can’t speak about the familly in this country? Because the law has been passed, we can’t express our convictions about what values we should pass to our children? No, I’m not like that,” said Vice President of the rightist UMP party Laurent Wauquiez.
Sunday’s demonstration saw three separate protests converge at Les Invalides in central Paris. A fourth was organised by Catholic group Civitas.
“We are here to defend marriage because we believe a child needs a father and a mother to grow up. This is important so that they develop normally,” said a young protester called Amelie.
“We were not heard, so we will come back as many times as necessary,” added fellow protester Isabelle Tchekhov.
France will see its first gay wedding when two activists tie the knot in Montpelier on Wednesday.
France is the 14th country to have legalised same-sex marriages.