France's rivals for the presidency, centrist frontrunner Emmanuel Macron and far-right challenger Marine Le Pen, are set to hold duelling rallies in Paris on Monday, the May Day holiday that will also see major demonstrations against both candidates.
Le Pen, 48, seeking to close a 19-point gap in voter surveys as her Sunday showdown with 39-year-old Macron looms, will take her case as "the people's candidate" to the working-class suburb of Villepinte.
The pro-business Macron's venue will be a modern convention centre near the La Villette science complex in northeastern Paris as he seeks to highlight his appeal as a future-oriented innovator.
Meanwhile, major demonstrations are planned in the city centre, one to protest against Le Pen and her anti-immigration National Front (FN), while another will be staged by people who reject both candidates.
For the first time in the history of the nearly 60-year-old Fifth Republic, neither candidate is from the traditional leftwing or rightwing party.
Also Monday, trade unions will stage traditional May Day demos and marches across the country, most calling for a "republican vote" to block Le Pen.
And in Paris, Le Pen's 88-year-old father Jean-Marie Le Pen -- whom she kicked out of the FN in 2015 -- will lead a march from a gilded statue of Joan of Arc, the FN's nationalist icon, to Paris Opera house.
Le Pen senior has repeatedly called the Nazi gas chambers a "detail" of history.
Hundreds of thousands of people took part in May Day events during the last presidential election in 2012, when the conservative Nicolas Sarkozy lost his re-election bid to the Socialist Francois Hollande.
But the same day 15 years ago -- when the anti-Semitic, xenophobic Jean-Marie Le Pen shocked France and the world by getting past the first round to face off with Jacques Chirac -- some 1.3 million people took to the streets against the FN candidate, including 400,000 in Paris.
People of all political persuasions rallied behind the conservative Chirac, who scored a landslide victory with 82 percent of the vote.
Marine Le Pen, who has worked to rebrand the FN to shed its associations with her anti-Semitic father, on Sunday laid a wreath at a World War II monument in the port of Marseille as France marked a day of remembrance for the victims of the mass deportation of Jews to Nazi Germany during World War II.
Macron, who if elected would become France's youngest president, paid his respects at Paris's Holocaust memorial, where he was greeted by France's grand rabbi, Haim Korsia.
The deportation of French Jews to Nazi Germany holds a highly sensitive place in the national psyche.
"What happened is unforgettable and unforgivable," Macron said at the Holocaust Memorial after pausing before a wall bearing the names of 76,000 Jews who were deported, of whom just 2,500 survived. "It should never happen again."
"The homage that I wanted to make today is this duty that we owe to all these lives torn down by the extremes, by barbarism," he said.
Earlier this month Le Pen was criticised for saying today's France bore no responsibility for the 1942 roundup and deportation of more than 13,000 Jews from a Paris cycling track.
Last week the FN became embroiled in controversy over the choice of an interim leader who had been accused of praising a Holocaust denier.
Jean-Francois Jalkh, who was tapped to lead the FN after Le Pen stepped aside to campaign for the presidency, was quickly replaced while Jalkh himself denied making the remarks.
- Endorsements for Macron -
Macron racked up several endorsements on Sunday, beginning with prominent French environmentalist Nicolas Hulot, who however said his backing was "not a blank cheque".
He also won praise from Airbus CEO Tom Enders, who wrote to him in a note carried by the daily L'Opinion: "The excitement you have created is fully merited. You embody change in a very concrete way."
And he received long-awaited support from eurosceptic Jean-Luc Melenchon, who crashed out of the race in the first round. The hard-left firebrand urged his supporters not to vote for Le Pen.
"I say to anyone who is listening: do not make the terrible error of voting for the National Front because you would push the country towards a general conflagration and the ending to which no-one can predict," he said on the TF1 television channel.
In a video message Friday, Le Pen had urged the nearly 20 percent of voters who backed Melenchon in the first round to "block" Macron, saying his pro-business programme was "diametrically opposed" to leftist ideals.