French voters began voting on Sunday in the first round of a snap parliamentary election that could usher in the country’s first far-right government since World War Two, a potential sea change at the heart of the European Union.

President Emmanuel Macron stunned the country when he called the vote after his centrist alliance was crushed in European elections this month by Marine Le Pen’s National Rally (RN). Her eurosceptic, anti-immigrant party was a longtime pariah but is now closer to power than it has ever been.

Polls opened at 0600 GMT and will close at 1600 GMT in small towns and cities, with an 1800 GMT finish in the bigger cities, when the first exit polls for the night and seat projections for the decisive second round a week later are expected.

However the electoral system can make it hard to estimate the precise distribution of seats in the 577-seat National Assembly, and the final outcome will not be known until the end of voting on July 7.

“We are going to win an absolute majority,” said Le Pen in a newspaper interview on Wednesday, predicting that her protégé, 28-year-old Jordan Bardella would be prime minister. Her party has a high-spending economic programme and seeks to reduce immigration.

If the RN does win an absolute majority, French diplomacy could be headed for an unprecedented period of turbulence: with Macron - who has said he will continue his presidency until the end of his term in 2027 - and Bardella jostling for the right to speak for France.

At a voting station in Sevres, on the outskirts of Paris, 70-year-old former company director Didier Delacroix said he had voted for Macron’s alliance.

“Otherwise it’ll be a complete mess,” he said.

France has had three periods of “cohabitation” - when the president and government are from opposite political camps - in its post-war history, but none with such radically divergent world views competing at the top of the state.

Bardella has already indicated he would challenge Macron on global issues. France could lurch from being a pillar of the EU to a thorn in its side, demanding a rebate of the French contribution to the EU budget, clashing with Brussels over European Commission jobs and reversing Macron’s calls for greater EU unity and assertiveness on defence.

A clear RN victory would also bring uncertainty as to where France stands on the Russia-Ukraine war. Le Pen has a history of pro-Russian sentiment and while the party now says it would help Ukraine defend itself against Russian invaders, it has also set out red lines, such as refusing to provide long-range missiles.

‘Split vote favors RN’

Opinion polls have suggested the RN has a comfortable lead of 33-36% of the popular vote, with a hastily assembled left-wing coalition, the New Popular Front, in second place on 28-31% and Macron’s centrist alliance in third on 20-23%.

The New Popular Front includes a wide range of parties, from the moderate centre-left to the hard-left, eurosceptic, anti-NATO party France Unbowed, led by one of Macron’s most vitriolic opponents, Jean-Luc Melenchon.

How the poll numbers will translate into seats in the National Assembly is hard to predict because of how the election works, said Vincent Martigny, professor of political science at the University of Nice and the Ecole Polytechnique.

Candidates can be elected in the first round if they win an absolute majority of votes in their constituency, but that is rare. Most constituencies will need a second round involving all candidates who received votes from at least 12.5% of registered voters in the first round. The top scorer wins.

“If you have a very high level of participation you might have a third or fourth party that is getting into the struggle. So then of course there’s a risk of split voting and we know that the split vote favours the National Rally,” said Martigny.

For decades, as the far right steadily gained popularity, voters and parties who did not support it would unite against it whenever it edged closer to national power, but that may not hold true this time.

Martigny said no one knew whether candidates from Macron’s camp would consider dropping out of the second round to give rivals from the left a chance of beating the RN, or the reverse.

Le Pen and Bardella have sought to make their party’s image more acceptable to the mainstream, for example by denouncing antisemitism. Le Pen’s father Jean-Marie Le Pen, founder and long-term leader of the RN’s forerunner, had a history of overtly antisemitic comments.

But critics say the RN’s courting of Jews is just a cover allowing it to deny accusations of racism while constantly stigmatising Muslims and foreigners.