Here are some key facts about the election and what comes next.
HOW DOES THE VOTE WORK?
France has 49 million registered voters. There are 577 constituency contests, one for each seat in the National Assembly, the lower house of parliament.
Candidates with an absolute majority of votes in their constituency are elected in the first round. In most cases no candidate meets this criteria and a second round is held.
To qualify for the run-off, candidates need first-round votes amounting to at least 12.5 percent of registered voters.
The top scorer wins the second round. WHEN WILL THE RESULTS BE ANNOUNCED?
Voting ends at 8 p.m.(1800 GMT), when pollsters publish nationwide projections based on a partial vote count. These are usually reliable. Official results start trickling in from 8 p.m. Vote counting is usually fast and efficient, and the winners of all, or nearly all, seats will be known by the end of the evening. WHO WILL RUN THE GOVERNMENT?
The president names the prime minister, usually from the party with most seats.
For the first time in France’s post-war history, the far right could win, opinion polls show, with a left-wing union seen winning the second-biggest group and President Emmanuel Macron’s centrist alliance coming third.
But this is an election like no other in France, campaign time is short, the electoral landscape is shaken, and other scenarios cannot be excluded.
These include a paralysed assembly divided into three groups with no one dominating it or an alliance of mainstream parties to keep the far right out of power.
An absolute majority requires at least 289 seats.
Marine Le Pen’s National Rally (RN) could run a minority government if it wins the most seats without reaching that threshold, but 28-year-old party leader Jordan Bardella said it wanted an absolute majority or would not be able to carry out reforms.
WHAT HAPPENS NEXT?
France has had three periods of “cohabitation,” where the government is of a different political stripe from the president, in its post-war history.
The government has most of the power on the domestic front, but the president is the head of the military and wields influence abroad. However, the division of power on foreign policy is not clear cut and that could be an issue for France’s stance on the war in Ukraine or European Union policy.
Macron will have to deal with the new parliament for at least a year, after which he can call another snap election.
Macron won a second mandate in April 2022 and is president for three more years. Neither parliament nor the government can force him out before that.