It was so large that organizers divided the protest against gay marriage into three columns with everyone merging in a park next to the Eiffel Tower. Organizers say 800,000 turned out while police put the total at a still impressive 340,000.
France’s Socialist government is planning to change the law this year.
But the demonstrators, backed by the Catholic Church and the right-wing opposition, argue it would undermine an essential building block of society.
The “Demo for all” event was being led by a charismatic comedian known as Frigide Barjot, who tweeted that the “crowd is immense” and told French TV that gay marriage “makes no sense” because a child should be born to a man and woman.
Although France allows civil unions between same-sex couples, Francois Hollande made a pledge to extend their rights part of his presidential campaign.
Centre-right UMP President Jean-Francois Cope said the rally would be a “test” for the president because there were “clearly millions of French people who are probably concerned by this reform”.
The far-right National Front is also opposed to the change, although its leader Marine Le Pen stayed away from the march, arguing the issue was a diversion by politicians from France’s real problems.
Despite the support of the Church and political right, the organisers are keen to stress their movement is non-political and non-religious, and in no way directed against homosexuals, BBC Paris correspondent Hugh Schofield reports.
An opinion poll of almost 1,000 people published by Le Nouvel Observateur newspaper at the weekend suggested that 56% supported gay marriage, while 50% disapproved of gay adoption.
The poll also said that 52% of those questioned disapproved of the Church’s stand against the legislation.
Earlier polls had indicated stronger support for the legalisation of gay marriage.
The protests come at a bad time for President Hollande who is struggling after a series of unforced errors in implementing his anti-rich, anti-business agenda.
But now as he starts 2013 and his eighth month as president, the Socialist’s clumsy handling of those promises has turned the public mood against him, created the impression among many entrepreneurs that he is anti-business and prompted smirking foreign leaders to offer refuge to French tax exiles.
Although Hollande and his parliamentary allies can look forward to a four-year run before facing re-election, those policy and PR gaffes risk hobbling him just as he embarks on what could be the decisive phase of his five-year mandate, with plans to set in motion long talked about labor, welfare and pension reforms in the euro zone’s second largest economy.
Mass protests in the streets have thwarted French presidents before, as have economic pressure and lobbying by business.
“He is struggling to explain the general sense of what he is doing. He needs to find a central message that is simple, credible and sounds like it will bring people benefits,” said veteran political communications consultant Denis Pingaud.
From the very beginning of his mandate, Hollande has had to walk a narrow political tight rope. Investors had long viewed him warily, especially since he declared a year ago that the “world of finance” was his enemy; meanwhile ordinary voters are impatient to see promised improvements in living standards.
If business feels scorned, voters, too, feel let down, by a failure to tackle a jobs crisis and by the fact that his most emblematic promise, a 75-percent tax rate on income above 1 million euros ($1.3 million), has been ruled unconstitutional.
Long in the doldrums, Hollande’s approval rating slid by a further four points in an Ifop opinion poll published this week to 37 percent. Another survey found three people in four doubt he can keep a promise to stem rising unemployment by end-2013.
The entire Euro-zone is in recession as fallout from the Greek, Spanish, and Italian debt troubles have slowed the economies of all. The unemployment rate for the EU is 11.8% — a record — and is two million higher than last year. Hollande’s policies do not promise growth on the scale he imagines, nor will his tax plans bring in the revenue he desires.
In short, the gay marriage protest is another indication that the French people have little confidence — a little liking — for Hollande and while they might like the idea of soaking the rich, they like the idea of economic growth more.