France opened its polling stations with the same candidates five years after the last presidential election.
Emmanuel Macron is a sitting president and is opposed to Marine Le Pen leader of the Rassemblement National party.
Both are candidates that could not bring more contrast: Mr Macron, from the center of politics; and Ms Le Pen, with more radical views.
A man who relies on big cities for his support is against a woman who relies heavily on small towns and rural areas for her support.
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The polling stations open at 8am (UK time) and close at 7pm. However, some centres in large cities can remain open until 8pm.
Already, voting has taken place in France’s overseas territories. Other countries with large French populations have also seen the installation of polling stations.
There are 16 of them in the UK – six in London and six in the rest.
After 8pm in France (or 7pm in the UK), exit polls are released. An official preliminary estimate based on early counts will follow shortly thereafter.
In addition to this, periodic updates will be made that update the overall result. The so-called “definitive result” will not be available until Monday, although the identity and winner may become known before then.
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After the second round of voting, two weeks ago, Ms Le Pen and Mr Macron emerged as the frontrunners. French voters were asked to vote between 12 candidates.
They have been campaigning for a fortnight across the country on a variety of topics. However, both candidates have placed a lot of emphasis on how France can deal with rising living costs.
A significant emphasis has been placed on foreign affairs, immigration and social cohesion. There have been significant differences between Ms Le Pen and Mr Macron in all these areas.
They only clashed in public once, when they faced off in a live debate on televised television that was viewed by 15.6 millions people.
This was the lowest number ever recorded for a live French presidential debate. However, it still represents a much larger audience than similar debates held in the United Kingdom.
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This time, a lot of attention will be paid to the turnout. There is speculation that voters may stay away from either candidate because they don’t like them.
Others feel they have an obligation to vote, but others will leave their ballot paper blank. This is referred to as a “white vote”.
Then there’s the question of what to do with the 20 million plus people who backed Jean-Luc Melenchon, the socialist candidate in the first round. He came third.
Will they support Ms Le Pen or the other radical?
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Before heading to Paris, Mr Macron will vote close to his northern seaside home of Le Touquet.
Ms Le Pen will also vote in northern France at Henin Beaumont before heading towards the capital to see the results.
Her team and she will be based in Pavillon d’Armenonville at the Bois de Boulogne. Macron’s team is creating their own Champ-de-Mars setting, near the Eiffel Tower.
Both Ms Le Pen (and Mr Macron) are experienced politicians who have been around for a while. However, their opinions on the future of the presidency are quite different. Both have been working hard to prepare for the decisive day, and both are desperate to win.
Only one can. One of them will be the one to lead this powerful, wealthy and influential country for five years, by Sunday’s end. The other will regret a missed opportunity and wonder if their political career is over.