Macron won 66 percent of the vote in Sunday's presidential run-off against the far right's Marine Le Pen.
Macron won 66 percent of the vote in Sunday's presidential run-off against the far right's Marine Le Pen, the biggest win by a French president since Jacques Chirac's victory over Le Pen's father Jean-Marie in 2002.
But he faces a tall order to convert his victory into the majority he needs to implement his ambitious agenda of labour, welfare and education reforms.
Le Pen's National Front (FN) and the other elections losers are all hell bent on bouncing back in the parliamentary vote.
Traditionally, French voters have handed a parliamentary majority to the newly elected president in the general election.
But for the first time in the country's post-war history, the new president does not have a big party machine behind him, with the two main governing parties, the Republicans and Socialists, crashing out in the first round.
Macron, 39, founded his centrist En Marche (On The Move) movement of mostly political neophytes just a year ago on a promise to inject new blood into France's discredited political class.
Half of his candidates for the 577 seats up for grabs in the general election will be newcomers to politics, he has said.
The other half will be made up of figures from the centrist Modem party with which he struck an alliance, as well as defectors from the centrist factions of the left-wing Socialists and right-wing Republicans.
"This majority for change is what the country wants and what it deserves," he told thousands of flag-waving supporters at a victory party in the courtyard of the Louvre Museum on Sunday.
Philippe Braud, professor emeritus at Sciences Po university in Paris, said Macron's decisive win on Sunday meant an outright majority -- deemed highly improbable just a few weeks ago -- was "not impossible".
Two polls showed that En Marche would top the first round of the June 11-18 election.
The polls by Kantar Sofres Onepoint and Harris Interactive showed En Marche winning 24-26 percent of the vote, ahead of the Republicans on 22 percent and the National Front on 21-22 percent.
The France Insoumise (France Unbowed) of firebrand left Jean-Luc Melenchon was shown trailing in fourth on 13-15 percent, ahead of the tattered Socialists of outgoing President Francois Hollande on 8-9 percent.
Within minutes of the results on Sunday, a defeated Le Pen sounded the charge for the general election.
Claiming a "massive" result of 33.9 percent -- a record for the FN -- she promised "a profound transformation" of the party to widen its appeal.
"I call on all patriots to join us," she appealed.
The FN, which has established itself as the voice of those who feel left behind by globalisation, is hoping to dramatically improve on its current tally of two seats in parliament.
But France's two-round voting system -- which favours consensus-driven figures at the final hurdle -- could stymie the party's ambition to become France's main opposition party.
Macron's biggest challenge is instead likely to come from the conservative Republicans, still smarting from defeat in a presidential election that looked theirs for the taking before their candidate Francois Fillon became embroiled in an expenses scandal.
"The resistance of the right is the main danger for Macron," said Braud.
A strong showing by the anti-capitalist Melenchon -- who has vowed to block Macron's plans for labour reforms -- would add to the uncertainty, making for an "ungovernable assembly," Braud added.
On Sunday, Francois Baroin, a leader of the Republicans, said his party was aiming for an "outright majority" in the general election -- a scenario that would force the centrist Macron into a "cohabitation" with a right-wing government.
Republicans vice-president Laurent Wauquiez emphasised Macron's vulnerability, noting he had been a grudging choice for many voters, who did not support his programme but were anxious to block Le Pen.
"Macron is a giant with feet of clay, elected without real desire of enthusiasm," he said.