Emmanuel Macron has won a resounding victory in the French presidential election but the focus will shift immediately Monday to whether he can govern the country without the support of a traditional party.

At 39, the pro-EU former investment banker will become France's youngest-ever president after crushing far-right leader Marine Le Pen in the run-off on Sunday, but he faces a formidable challenge to enact his policy programme while trying to unite a fractured and demoralised country.

He has proposed an ambitious domestic reform agenda including cutting state spending, easing labour laws, boosting education in deprived areas and extending new protections to the self-employed.

But he is inexperienced, has no political party and must fashion a working parliamentary majority after legislative elections next month.

There is scepticism about Macron's ability to win a majority with candidates from his En Marche movement -- "neither of the left, nor right" -- alone, meaning he might have to form a coalition.

"In order for us to act, we will need a majority in the National Assembly," En Marche secretary general Richard Ferrand told TF1 television, adding that only "half of the journey" had been completed. 

And his economic agenda, particularly plans to relax labour regulations to fight stubbornly high unemployment, is likely to face fierce resistance from leftist opponents.

He also inherits a country still in a state of emergency following a string of Islamist-inspired attacks since 2015 that have killed more than 230 people.

- Plea for unity -

"I will fight with all my strength against the divisions that are undermining us," Macron said in a solemn speech at his campaign headquarters Sunday.

A sea of jubilant supporters waving French flags celebrated outside the Louvre Museum in Paris as the extent of Macron's victory sank in.

With 99.99 percent of ballots counted early Monday, Macron had 66.06 percent of the vote in the first ever election he has contested, far ahead of the nationalist Le Pen at 33.94 percent. Turnout was 74.62 percent.

But in a sign of widespread disillusionment, one in three voters abstained or cast a blank ballot.

Western leaders largely hailed the result after the shock of Britain's vote to leave the EU and the election of Donald Trump in the United States.

Macron reached out to Le Pen's supporters in a plea for unity after a vicious election campaign that exposed deep economic and social divisions, as well as tensions provoked by identity and immigration.

"They voted out of anger, distress and sometimes conviction. I respect them," he said. "I will do everything I can over the next five years to ensure that people no longer have any reason to vote for extremes," he said.

According to a poll Monday, En Marche will receive between 24 and 26 percent of votes in legislative elections, with the Republicans party on 22 percent, the National Front 21-22 percent, the far-left France Insoumise (France Unbowed) 13 -15 percent and the Socialist Party 8-9 percent.

Macron walked on to the stage to the strains of "Ode to Joy", the anthem of the beleaguered European Union that he has promised to strengthen after Britain's impending exit.

His 64-year-old wife Brigitte joined him on stage with her children and grandchildren. 

"He's a symbol of hope," said Jean-Luc Songtia, a 36-year-old driver. "It's like Obama eight years ago. It's youth, it's hope."

His first ceremonial duty comes on Monday when he appears alongside outgoing Socialist President Francois Hollande in Paris to commemorate the defeat of Nazi Germany on May 8, 1945.

- Sigh of relief -

Unknown three years ago, Macron is poised to become one of Europe's most powerful leaders and the result will resonate worldwide, particularly in Brussels and Berlin where leaders will breathe a sigh of relief at the defeat of Le Pen's anti-EU, anti-globalisation programme.

German Chancellor Angela Merkel's spokesman said it was a "victory for a strong and united Europe" and the two had a "very warm" telephone call after his victory was announced, Macron's team said.

British Prime Minister Theresa May discussed Brexit with Macron in a call to congratulate him late Sunday, her office said.

Trump, whose beliefs are seen as radically different to Macron's, tweeted congratulations on a "big win" and said he looked forward to working with him.

The euro briefly rallied to a six-month high against the dollar in Asian trade and other financial markets are expected to react positively.

"It is a big victory for a part of the population -- and there are many of them -- who identify closely with Europe and a certain vision of globalisation," political analyst Philippe Braud told AFP.

The French election had been widely watched as a test of how high a tide of right-wing nationalism would rise after Brexit and Trump.

Le Pen, 48, had portrayed the election as a contest between Macron and "globalists" -- those in favour of open trade, immigration and shared sovereignty -- and her "patriotic" vision of strong borders and national identities.

In a short speech to supporters, Le Pen claimed a "historic, massive result" and said she had called Macron to wish him success in tackling the country's challenges.

She said her party needed to undergo a "profound transformation" ahead of parliamentary elections in June. One of her aides said the party will change its name.

Source: AFP