French voters are heading to the polls to decide whether to give centrist Emmanuel Macron five more years as president or replace him with far-right candidate Marine Le Pen.
After a divisive election campaign, Ms Le Pen faces an uphill battle with her 44-year-old opponent polling ahead.
In order to win they both need to attract voters who backed other candidates in the first round.
But these are two polarizing figures in France and abstention is a key factor.
Mr Macron’s detractors call him arrogant and a president of the rich, while the far-right leader has been accused of having ties to Russian President Vladimir Putin.
Some 48.7 million people are eligible to take part and by midday (10:00 GMT) turnout was down five years ago at 26.4%, but not as low as in the first round two weeks ago. First projections of who has won will come at 20:00.
Marine Le Pen was the first of the two candidates to vote, which she did in her stronghold in Hénin-Beaumont. As she arrived, she sheltered a baby boy from the sun and told him: “I will protect you.”
Mr Macron rose to power on a whirlwind promise of change, but many complain they are yet to see it. His presidency has been buffeted by protests, the Covid pandemic and now the rising cost of living.
Marine Le Pen, meanwhile, has learned from the mistakes she made when she was resoundingly beaten by the same opponent in the second round in 2017. This is her third tilt at the presidency and if she fails it could be her last.