Far-right leader Marine Le Pen and centrist Emmanuel Macron have advanced to a run-off in the French presidential election.

Counting of 47 million votes in the election first round put Mr Macron on 23.8% of the vote and Ms Le Pen on 21.5%.

The pair will now face a run-off vote on May 7 - something many polls suggest Mr Macron will win.

Defeated candidate François Fillon, of the centre-right, registered 19.91% of the vote, while hard-left nominee Jean-Luc Mélenchon took 19.64%.

As the standings became clearer, French politicians on the left and right urged voters to block Ms Le Pen's path to power.

  • Why is the election important?

The selection of Ms Le Pen and Mr Macron presents voters with the starkest possible choice between two diametrically opposed visions of the European Union's future and France's place in it.

Ms Le Pen wants France to leave the EU and Mr Macron wants even closer cooperation between the bloc's 28 member states.

For the first time in modern French history, no mainstream party candidate is advancing, upending the country's political system.

The country is going to the polls to elect the successor to Francois Hollande, who is not running after serving a single term in office.

Voting took place amid heightened security in the first election under France's state of emergency, which has been in place since gun-and-bomb attacks in Paris in 2015.

  • What do Macron and Le Pen stand for?

Mr Macron is pro-European. Credit: AP

Pro-European Mr Macron was the Socialist finance minister until the autumn, when he quit to set up the En Marche movement, which he defines as centrist, and which has attracted support from left, centre and right.

The anti-EU Ms Le Pen's campaign majored on jobs, security and the threat from Islamic extremism.

It also saw her deny French state complicity rounding up Jews for the Nazis in the Second World War.

Ms Le Pen is fiercely anti-EU. Credit: AP

As the votes were counted on Sunday, Ms Le Pen said she was offering "the great alternative" in the presidential race and that the debate over globalisation "is open".

Mr Macron addressed his supporters saying he sought national unity and hopes in Europe.

Mr Macron said: "In a year we have changed the face of French politics."

  • What has the reaction been?

Anti-Le Pen protesters clashed with police in Paris. Credit: AP

The French prime minister has called on voters to reject far-right leader Ms Le Pen in the runoff and vote for Mr Macron.

Defeated candidate Francois Fillon urged the same, saying: "Extremism can only bring unhappiness and division to France.

"As such, there is no other choice than to vote against the extreme right."

European Commission President Jean-Claude Juncker also congratulated Mr Macron.

Thanking Mr Fillon for his endorsement, Mr Macron said: "Tonight I start to gather together the French people.

"I want to thank the millions of Frenchwomen and Frenchmen who voted for me."

Meanwhile, protesters clashed with police in Paris on Sunday as they voiced disapproval at both candidates' advances.