Macron will be inaugurated on Sunday and the centrist's victory is threatening to rapidly re-draw the French political map.
Macron will be inaugurated on Sunday and the centrist's victory over far-right leader Marine Le Pen is threatening to rapidly re-draw the French political map.
The bruising contest left the traditional parties of left and right on the sidelines, and the governing Socialist Party in particular is in tatters after the two-round election.
After former prime minister Manuel Valls shocked the party by saying it was "dead" and he wanted to be a parliamentary candidate for Macron's year-old "Republique on Marche" (Republic on the Move) movement, another leading Socialist struck out on Wednesday.
Benoit Hamon, who as the Socialist presidential candidate finished fifth in the first round of the election, said he planned to launch a new leftwing movement.
Hamon vowed to "rebuild the left" with a new "broad-based movement", while saying he intended to remain a member of the Socialist Party.
Left-winger Hamon beat centrist Valls to secure the Socialist nomination for the election after an ideological battle within the party.
But he won just 6.4 percent of the first-round presidential vote on April 23, after being overshadowed by Communist-backed leftwinger Jean-Luc Melenchon.
Hamon said his movement would be launched on July 1, after legislative elections in June that are crucial to Macron's chances of enacting his programme.
Macron, 39, has promised to rejuvenate France's jaded governing class by bringing more people into parliament who, like him, have never held elected office.
The incoming president has said half of the candidates for the 577 seats up for grabs in the two-round June 11-18 elections to the National Assembly will be new to politics.
The rest will be from the centrist Modem party or rebels from the Socialists and right-wing Republicans -- and he will likely need to form a coalition to govern.
A representative of Republic On the Move said Wednesday that Valls had "not yet" fulfilled the criteria to be a candidate.
The candidates will be announced by Thursday.
The ramifications of Macron's victory were also reverberating through Le Pen's National Front (FN), with the announcement that her influential niece Marion Marechal-Le Pen is quitting politics -- for now.
Marechal-Le Pen, 27, who has been tipped as a future leader of the party, said in a letter to a regional newspaper in southern France that she would resign her parliamentary seat because she wanted to work in the "business world" and spend more time with her young daughter.
Behind her decision though is a battle for the far-right party's future between the more socially progressive wing led by her aunt and the more Catholic, conservative branch based in the south of France represented by Marechal-Le Pen.
She was openly critical of Marine Le Pen's score of 33.9 percent against Macron, reflecting the opinion of many critics of her aunt that a score of below 40 percent was a failure.
Marine Le Pen, a mother of three children, tweeted that "as a political leader I deeply regret Marion's decision but, alas, as a mum, I understand it".
Macron meanwhile was mobbed after he took part in a ceremony in the Jardin du Luxembourg in Paris with Hollande to commemorate the abolition of slavery.
The incoming president was surrounded by wellwishers for around an hour after the ceremony.
Meanwhile, the head of the US National Security Agency said Russia was behind the 11th-hour hack of Macron's campaign team 36 hours before voting and that it was US officials who had informed France that a cyber-attack was underway.
"We had become aware of Russian activity," Admiral Mike Rogers told a US Senate hearing on Tuesday.
Thousands of files were leaked online and although they were spread by groups including WikiLeaks, French election law prevented any reporting of their contents in the mainstream media.