Voting was underway in France on Sunday in a parliamentary election that could deprive centrist President Emmanuel Macron of the absolute majority he needs to govern with a free hand.
Voting started at 8:00 am (0600 GMT), with initial projections expected at 8:00 pm (1800 GMT) in an election that could change the face of French politics.
Pollsters predict Macron's camp will end up with the biggest number of seats, but say it is in no way guaranteed to reach the 289 threshold for an absolute majority.
Opinion polls also see the far right likely to score its biggest parliamentary success in decades, while a broad left-green alliance could become the largest opposition group and the conservatives find themselves as kingmakers.
In Sevres, just outside Paris, where light rain provided some relief after a major heatwave hit France on Saturday, some voters said environmental concerns had motivated them to cast a ballot for the Nupes left-wing alliance.
"During the past 5 years, the presidential majority wasn't able to meet the challenges of climate change – the current heatwave makes you want to support environmental projects even more," Leonard Doco, a 21-year-old film student, told Reuters.
Others said they didn't trust the leader of the left-wing bloc, firebrand Jean-Luc Melenchon, who has campaigned under the slogan "Elect me prime minister" and promises to cut the retirement age to 60 from 62, freeze prices and ban companies from firing workers if they pay dividends.
Overnight, results of France's overseas department brought bad news for Macron, with his minister for maritime affairs losing in her Caribbean constituency. Some 15 ministers are running in this election and Macron has said they'll have to quit if they lose.
If Macron's camp does fall short of an outright majority, that would open a period of uncertainty that could be solved by a degree of power-sharing among parties unheard of in France over the past decades - or result in protracted paralysis and repeat parliamentary elections down the line.
Macron, who wants to push up the retirement age, pursue his pro-business agenda and further European Union integration, won a second term in April.
After electing a president, French voters have traditionally used legislative polls that follow a few weeks later to hand him a comfortable parliamentary majority - with Francois Mitterrand in 1988 a rare exception.
Macron and his allies could still achieve that.
But the rejuvenated left is putting up a tough challenge, as rampant inflation that drives up the cost of living sends shockwaves through the French political landscape.
If Macron and his allies miss an absolute majority by just a few seats, they may be tempted to poach MPs from the centre-right or conservatives, officials in those parties said.
If they miss it by a wider margin, they could either seek an alliance with the conservatives or run a minority government that will have to negotiate laws on a case-by-case basis with other parties.
Even if Macron's camp does win the 289 seats or more it needs to avoid sharing power, it is likely to be thanks to his former prime minister Edouard Philippe, who will be demanding more of a say on what the government does.
So after five years of undisputed control, Macron, known for his top-down approach to power, is looking at a new mandate where he will need to strike more compromises.
No poll has shown the leftwing Nupes led by Melenchon winning a ruling majority - a scenario that could plunge the euro zone's second largest economy into a tense period of cohabitation between a president and prime minister from different political groups.