Officially a secular republic, France is overwhelmingly Catholic, and the issue of gay adoption and marriage -- a key campaign pledge of Socialist President Francois Hollande -- has caused deep divisions.
On Sunday, at least 150,000 demonstrators took to the streets of Paris in a last-ditch protest to denounce the new law. The largely peaceful gathering later turned violent as riot police battled hundreds of right-wingers.
The country's first gay couple to marry will be 40-year-old Vincent Aubin and Bruno Boileau, 30, in Montpellier, known to homosexuals as the "French San Francisco" because of its gay-friendly reputation.
Boileau is keenly aware that the nuptials at Montpellier's town hall -- which follow a five-year relationship -- will be a media circus with at least two cabinet ministers and 600 people attending, including 130 accredited journalists.
"It could be intimidating," Boileau said. "But we will try to retain the spirit of the goal -- equality for all. That Mister or Miss Anybody can get married in the town hall."
France is the 14th country to legalise same-sex marriage, an issue that has also divided opinion in many other nations.
Opposition to the move started as a grassroots campaign which was backed by the influential Roman Catholic church. The right-wing opposition then jumped into the fray and the movement ballooned.
On Sunday, French police made a total of 293 arrests and said six people were injured -- four police officers, a photographer and a protester. Interior Minister Manuel Valls blamed the extreme right for the violence.
The definitive vote in the French parliament came on April 23 when the law was passed legalising both homosexual marriages and adoptions by gay couples.
Montpellier's mayor Helene Mandroux, who had symbolically married two homosexuals -- Tito Livio Santos Mota and Florent Robin -- on February 5, 2011 before the legislation was approved, said she did not want a media circus.
"I am not a celebrity type," she said. "I am into values. I have told everyone: This moment should be a moment that is respectful of the event."
The marriage vows have been honed down to a simple: "Do you take this man as your spouse?"
After the ceremony, the newlyweds plan to publicly thank those who battled for homosexuals to have the right to marry. But the local administration has banned festivities outside the venue, fearing protests.
According to a survey published Sunday in the Journal du Dimanche, nearly three-quarters of French people are tired of the anti-gay marriage protests and think they should stop.
Get the latest election news, live updates and election schedule for Lok Sabha Elections 2019 on ndtv.com/elections. Like us on Facebook or follow us on Twitter and Instagram for updates from each of the 543 parliamentary seats for the 2019 Indian general elections.