Amid heightened security, French voters began casting ballots for their next president Sunday in a first-round poll that’s seen as a litmus test for the spread of populism around the world and a vote on the future of Europe.

More than 50,000 police and gendarmes were deployed to the 66,000 polling stations for Sunday’s election, which comes after Thursday’s deadly attack on the Champs-Elysees in which a police officer and a gunman were slain. The presidential poll is the first ever to be held during a state of emergency, put in place since the Paris attacks of November 2015.

Voters are choosing between 11 candidates in the most unpredictable contest in decades.

The vote “is really important, mainly because we really need a change in this country with all the difficulties we are facing and terrorism,” said Paris resident Alain Richaud, who was waiting to cast his vote.

Opinion polls point to a tight race among the four leading contenders vying to advance to the May 7 presidential runoff, when the top two candidates will go head to head.

Polls suggest far-right nationalist Marine Le Pen and Emmanuel Macron, an independent centrist and former economy minister, were in the lead. But conservative Francois Fillon, a former prime minister, who was embroiled in a scandal over alleged fake jobs appeared to be closing the gap, as was far-left candidate Jean-Luc Melenchon.

France’s 10 percent unemployment, its lackluster economy and security were issues that top concerns for the 47 million eligible voters.

The election is widely seen as a vote on the future of the European Union — with most of the candidates railing against its institutions.

Both Le Pen and Melenchon — two candidates from opposite extremes of the political spectrum — could pull France out of the 28-nation bloc and its shared euro currency in a so-called “Frexit.”

A French exit could spell the end of the EU.

If either candidate wins a spot in the runoff, it will be seen as a victory for the rising wave of populism reflected by the votes for Donald Trump in the U.S. and Brexit in Britain.

“It’s definitely risky, but I have faith in the result even if an extreme candidate qualifies for the second round,” said Beatrice Schopflin, who was queuing to vote in Paris.

Macron and Fillon are committed to European unity and would reform labor rules.

The candidates are voting throughout the day.

Meters from the polling station where Le Pen was heading to vote, several feminist activists from the Femen group were arrested after staging a topless protest against the far-right leader, who is the only major female contender in the race. Police intervened and stopped the commotion minutes before the 48-year-old arrived to cast her ballot in the northern town of Henin-Beaumont. No one was hurt.

Macron, meanwhile, was the image of serenity as he posed for selfies with voters after casting his ballot in the coastal town of Le Touquet in northern France alongside his wife, Brigitte Macron.

Fillon voted in Paris, but his wife — who’s been handed preliminary charges for her role in the fake jobs scandal that rocked her husband’s campaign — voted 250 kilometers (155 miles) away from him near their 14th century manor house in Sarthe.

This year’s roller-coaster campaign has seen much controversy, but some voters appear to have become blas? or turned off from politics.

“There have been surprises, there have always been scandals,” said Le Touquet resident Pierre-Antoine Guilluy.

Voter Marie-Christine Colrat said: “Listen, too many candidates. And candidates that caused us a lot of problems, I think that’s not a good thing for France.”

Unpopular incumbent President Francois Hollande, who pledged last year not to stand for re-election, voted in his political fiefdom of Tulle in Correze, southwestern France.

This year’s Socialist party presidential candidate Benoit Hamon cast his ballot in Trappes, a Paris suburb. Melenchon also voted in Paris.

Political campaigning was banned from midnight Friday hours ahead of polls opening in France’s far-flung overseas territories such as Guadeloupe, French Polynesia and French Guiana, which all voted a day early Saturday.

(AP)