Tens of thousands of people have marched in central Paris in a fresh protest against the legalisation of same-sex marriage.

The move has deepened political polarisation and worsened the plight of the unpopular government of Francois Hollande.

The historic Esplanade des Invalides was transformed into a sea of protesters waving pink and blue flags, while far-right demonstrators hung a banner on the ruling Socialist Party headquarters calling for President Hollande to quit.

The protests, which began as a grass-roots campaign backed by the Roman Catholic Church, have morphed into a wider movement with opposition politicians and the far right airing discontent with Hollande.

Although more than half of French people support the law allowing same-sex marriage and adoption, and more than 70% believe protests should now stop, mass rallies have added to Mr Hollande's woes.

Plagued by economic recession, with unemployment at more than 10% and pressure to cut the deficit, the leader had some respite yesterday with news his popularity was up four points to 29% this month.

Although it failed to block gay marriage, the protest movement hopes its show of force will stop or slow down further laws allowing assisted procreation and surrogate motherhood for gay couples.

Interior Minister Manuel Valls mobilised 4500 police to secure yesterday's event. "We fear some action by far-right groups," he said.

Leaders of Hollande's Socialist Party denounced the protest against a law already passed.

France's first gay wedding will take place on Wednesday in Montpellier, France's self-proclaimed capital of gay culture.