France's presidential contenders Emmanuel Macron and Marine Le Pen raced on the last day of campaigning on Friday to drive home why their particular political brand is the right choice for voters.

Mr Macron, the centre-right incumbent, laid into the nationalist rival he is set to face in a Sunday run-off, accusing the far-right leader of trying to divide France over Islam.

"The far right lives off fear and anger creating resentment. It says that excluding parts of society is the answer," Mr Macron told France Inter radio. "(But) I want to try to answer it... (and) make us live as a united nation."

Lagging behind Mr Macron in the latest opinion polls, Ms Le Pen campaigned in her stronghold of northern France in a last-ditch effort to try to close the gap.

In a gritty mood, Ms Le Pen lashed out at Mr Macron's planned pensions reform, which she described as an effort to make the French work forever.

"The French, with Emmanuel Macron, will end up with life," Ms Le Pen said. "This reform of Emmanuel Macron is a deep social injustice."

In a bid to seduce working-class voters and electors who cast some 7.7 million votes for leftist candidate Jean-Luc Melenchon in the first round, Mr Macron has watered down a campaign pledge to raise the retirement age in France to 65 by 2030.

He now says he will consult with unions before deciding on the new legal retirement age.

Mr Macron acknowledged that Ms Le Pen had alacrity and resonance among some voters, adding that "she has managed to draw on some of what we did not manage to do, on some of the things I did not manage to do to pacify some of the anger, respond quickly to what voters want."

The two candidates must make their final pitches to the French electorate before campaigning for the presidential run-off is legally required to end at midnight.

Mr Macron was later set to travel to Figeac, a town deep in France's southern heartland where Mr Melenchon came in second place in the first round of voting, and was due to speak there during the afternoon.

Ms Le Pen was in Etaples, at a marketplace near Le Touquet - a pointed choice on the final day of campaigning given that it is the constituency in which Mr Macron himself votes.

The National Rally leader displayed a combative spirit following a bitter televised debate with Mr Macron this week that buoyed some of her poll numbers.

Speaking on C-News, Ms Le Pen called on the French to read her manifesto and wake up to the failures of Mr Macron's five-year term. She responded to criticism that her policies did not hold up under scrutiny.

"I call on the French to check for themselves and form an opinion by reading what I propose to do to respond to the rampage that was Emmanuel Macron," she said.