Voters in France will head to the polls on Sunday, in what will most probably be the first of a two-round election to choose a new president of the republic.

The election will be a closely fought contest, particularly between four of the 11 candidates in the race.

The fact that there are 11 candidates may prevent a decisive victory, with many analysts predicting that a vote of more than 50 percent, required for an outright win, is unlikely to be achieved by any of the leading contenders.

In the event that no candidate secures an absolute majority, a second round of voting - pitting the two top candidates against each other - will take place on May 7.

All projections stipulate a run-off between the 48-year-old leader of France's far-right National Front (FN) Marine Le Pen and the young centrist independent candidate Emmanuel Macron, 39.

But the battle will not be easy, as both conservative party candidate Francois Fillon and leader of the far left Jean-Luc Melenchon are projected to do well in the first round.

The final result will be announced at 8pm on Sunday.

Opinion polls in France have repeatedly suggested that turnout in the first round will be low. Only about 65 percent of the electorate plan to vote, and up to 50 percent of the 47 million voters remain undecided on their vote.

The 30 percent who are planning to abstain would help set a record low turnout.

Pollsters say a low turnout favours Le Pen, whose supporters are the most determined to vote.

This year's elections were marred by a shooting incident in central Paris, after an attacker opened fire on a police van on the Champs Elysees on Thursday night, killing one officer and seriously wounding two others.

READ MORE - French Election 2017: Who I'll vote for

It also comes within a year of the unexpected Brexit vote in the UK and the election of populist Donald Trump as president of the United States last November.

In France, the possibilities are no less dramatic with the steady advance of the far-right National Front's Marine Le Pen.

Who will win?

According to pollsters, Le Pen, an anti-European Union candidate, is expected to reach the second round but ultimately lose to Emmanuel Macron.

A Le Pen victory would send shockwaves every bit as seismic as events in the UK and US, probably spelling the end of the EU in its current form.

Her victory would also test the country's already strained relations with its sizeable Muslim community.

Macron, Le Pen's main challenger and favourite to win, has campaigned on a pro-EU, pro-status quo, centrist outlook, hoping to secure support from those weary of the disruption an unknown quantity, such as Le Pen, may bring.

But Le Pen is not alone in promising major change.

Along with the conservative Francois Fillon, who is 63, the leftist Jean-Luc Melenchon, 65, favours a rapprochement with a Russian government increasingly at odds with the Western order.

Like Le Pen, Melenchon is a Eurosceptic who has promised a referendum on the country's continued membership of the bloc.

While pro-EU, Benoit Hamon, the 49-year-old Socialist Party candidate, is no less radical. He has promised the eventual introduction of a basic income for all French citizens.

The other six candidates include a leftist economics teacher, an anti-American nationalist convinced that the EU is a CIA-backed plot, and a conspiracy theorist who has before called for a "thermonuclear corridor" between Earth and Mars.

None of them is expected to win more than 5 percent of the vote.