The legislation, a key election pledge of Socialist President Francois Hollande, was passed by 329 votes to 229 in the National Assembly yesterday and must now win final approval in the Senate, or upper house of Parliament.
The vote came 10 days after lawmakers overwhelmingly voted to adopt its key article which redefines marriage as a contract between two people rather than between a man and a woman.
A campaign orchestrated by the Catholic Church and belatedly backed by the mainstream centre-right opposition steadily gathered momentum throughout the autumn and culminated in a giant protest in Paris last month.
Somewhere between 340,000 and 800,000 demonstrators flooded into the capital in a protest that was at least twice the size of a pro-gay marriage march staged later in the month.
In September, Cardinal Philippe Barbarin, the Archbishop of Lyon, claimed the Government's plans to redefine the concept of marriage would open the door to incest and polygamy.
That prompted Bertrand Delanoe, the Mayor of Paris and one of France's few openly gay politicians, to say the elderly cleric must have "flipped his lid."
Similar withering criticism was directed at Serge Dassault, a prominent industrialist who suggested the French would die out after being consumed by the same decadence that led to the fall of ancient Greece.
"We'll have a land of homos," Dassault claimed. "And then in 10 years there will be no-one left. It's stupid."
Throughout all the turmoil, Hollande's support for the legislation has not wavered and his girlfriend, Valerie Trierweiler, has revealed that the President will be attending the marriages of gay friends once the legislation is on the statute books.
That is expected to happen by the middle of this year, as the Socialists enjoy an outright majority in Parliament and the proposed reform is also supported by the Greens, Communists and some centrists.