French President Francois Hollande on Monday urged voters to reject far-right leader Marine Le Pen in next month's presidential runoff against pro-EU candidate Emmanuel Macron.
Macron is the clear favourite to become France's youngest-ever president after topping Sunday's first round of voting with 24.01 percent of votes, ahead of National Front (FN) leader Le Pen on 21.30 percent, according to final results.
The vote revealed a country deeply divided, with 39-year-old Macron, an advocate of open borders and free trade, leading the vote in cities and Le Pen topping the polls in rural areas that feel left behind by globalisation.
In a solemn address to voters, Hollande warned of the "risk for our country" of a far-right victory and said he himself would vote for Macron, who served as his economy minister for two years.
The Socialist president joined a long line of politicians urging voters to back Macron in order to thwart the anti-immigration, anti-EU Le Pen.
Le Pen seized on the flurry of endorsements for Macron from the ruling Socialists and main opposition Republicans -- both of which crashed out in the first round -- as proof he was the choice of the discredited old guard.
Visiting a market in the northern town of Rouvroy on Monday, 48-year-old Le Pen lashed out at the "rotten old republican front" -- the ad-hoc anti-FN coalition formed by mainstream parties whenever the party is at the gates of power.
"I've come here to start the second round campaign in the only way I know -- on the ground with the French people," she said.
Macron received several congratulatory calls on Monday from European leaders relieved to find him in pole position.
Thanking Hollande in a tweet for his support, the former investment banker called on the French to "remain true to France's values" in the May 7 runoff.
He and Le Pen will take part in a TV debate on May 3.
France's traditional political class suffered a stunning blow on Sunday, with voters fleeing the ruling Socialists and conservative Republicans who have governed for the past half century in favour of the extremes or outsiders.
Both Macron and Le Pen campaigned as rebels who transcended the left-right divide.
Conservative candidate Francois Fillon was seen as the favourite until January when his campaign was torpedoed by allegations that he gave his British-born wife and two of his children fictitious jobs as parliamentary assistants.
In the end, the Republicans party candidate trailed in third with 20.01 percent, ahead of radical left candidate Jean-Luc Melenchon on 19.58 percent.
On Monday, Fillon told the party's top brass he lacked "the legitimacy" to lead them into parliamentary elections in June.
"I need to rethink my life and heal my family's wounds," he told them, according to a statement.
Fillon and fifth-placed Socialist candidate Benoit Hamon have both rallied behind Macron but Melenchon pointedly avoided endorsing the centrist.
'Patriots v nationalists'
Addressing thousands of flag-waving supporters in Paris on Sunday evening, Macron said he aimed to unite "patriots" against "the threat of nationalists".
Le Pen, who has been hoping to emulate Donald Trump's victory in the US, said the French faced a choice between "runaway globalisation" and a protectionist France.
Her plans to restore France's borders with its European neighbours, pull out of the eurozone and hold a referendum on leaving the EU had sown fear of another devastating blow to the bloc after Britain's vote to leave.
The euro and European stocks rose Monday, buoyed by polls suggesting Macron would beat Le Pen by more than 20 percentage points in the second round.
After addressing euphoric supporters in Paris on Sunday, Macron spent the evening with friends at a well-known Paris bistro, drawing criticism for what some saw as his triumphalist attitude.
"We need to be humble. The election hasn't been won and we need to bring people together to win," Richard Ferrand, secretary general of Macron's En Marche (On the Move) movement, acknowledged on BFM television Monday.
Le Pen gained over 1.2 million new voters compared with her last presidential bid in 2012, securing 7.7 million ballots, a result she hailed as "historic".
But her share of the vote was far below a March poll high of 27 percent.
She follows in the footsteps of her father Jean-Marie, who made it through to the 2002 presidential run-off in what was a political earthquake for France.
Le Pen senior went on to suffer a stinging defeat when mainstream parties closed ranks to keep him out.
Sunday's first round capped a rollercoaster campaign in a demoralised France, which has been rocked by a series of terror attacks since 2015 and is struggling to shake off a deep economic malaise.
Le Pen seized on a jihadist attack that claimed the life of a policeman in Paris three days before the vote to stress her tough line on immigration and security, but the attack did not appear to sway voters.