Emmanuel Macron may have won Sunday's presidential election by a comfortable margin, but even his supporters' enthusiasm is tempered by the scale of the challenge that the inexperienced politician faces in tackling France's deep-seated economic, social and security problems.
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.
Macron's En Marche party now has no seats in parliament, though an opinion poll last week predicted it would emerge as the largest in the parliamentary elections next month.
An Elabe poll for BFM TV found that 52 percent of those polled wanted Macron's party to get a majority in parliament while 47 percent wanted opposition lawmakers to hold a majority.
Her score this time round was almost double that of her father when he shocked France and the world by making it into the second round of the presidential election in 2002, in which he was ultimately defeated by Jacques Chirac when left- and right-wing voters joined forces to keep the extreme right out of the Elysée.
International Monetary Fund (IMF) Managing Director Christine Lagarde kisses Emmanuel Macron (when French Economy Minister) at the OECD headquarter in Paris, October 17, 2014.
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.
Amid a sea of red, white, and blue tricolor flags at a victory party outside the iconic Louvre Museum in Paris on May 7, Macron said the country was turning a page in its history and pledged to the thousands in attendance to defend France and Europe and "rebuild links between Europe and its citizens".
All 577 seats in France's lower chamber are up for grabs in the country's two-part June 11 and June 18 parliamentary election.
The Republicans, the main center-right party whose candidate like that of the Socialists was eliminated in a first vote for president on April 23, were preparing on Wednesday to unveil a policy platform that softens some of the hardline measures it was proposing during the presidential campaign.
"I will be candidate for the presidential majority and I wish to join the list (of candidates) of his movement", Valls, a Socialist, told RTL radio.
The French interior ministry said on Monday the centrist candidate had been elected president with 66.06 per cent of valid votes cast in Sunday's runoff election, after accounting for all but 0.01 per cent of France's 47 million registered voters.
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". "(Vall's) voice is not insignificant, but his candidacy will be treated like anyone else's". "The essential thing today is to give a broad and coherent majority.to Emmanuel Macron to allow him to govern", he said. As a former minister in a Socialist government, he could send a bold signal by appointing a prime minister from the opposite political tribe, the centre right.