Paris: President Emmanuel Macron has won a commanding majority in France's parliamentary election, sweeping aside traditional parties and securing a powerful mandate for pro-business reforms.

The result, based on official figures and pollster projections, redraws the country's political landscape, humiliating the Socialist and conservative parties that alternated in power for decades until Macron's election in May.

Three pollsters projected that Macron's Republic on the Move (LREM) and its Modem allies would win 355 to 365 seats in the 577-seat lower house after the second round ballot, fewer than previously forecast.

They predicted the conservative Republicans and their allies would form the largest opposition bloc with 125 to 131 seats, while the Socialist Party, in power for the past five years, and its partners would secure 41 to 49 seats, their lowest ever in the postwar Fifth Republic.

Official figures with 90 seats still left to be decided show LREM has already won its majority.

"This is an opportunity for France. One year ago no one would have imagined such a political renewal," Prime Minister Edouard Philippe said in a statement.

Voter turnout was projected to be a record low at about 42 per cent. The high abstention rate underlines that Macron will have to tread carefully with reforms in a country with muscular trade unions and a history of street protests that have forced many a past government to dilute new legislation.

"People know it's already a done deal," Alex Mpoy, a 38-year-old security guard, said in Paris, echoing the apathy of many voters who did not intend to vote.

Winners and losers

Far-right leader Marine Le Pen won a seat in the National Assembly for the first time. Her National Front party clinched at least eight seats in total, a result she celebrated but which may disappoint supporters who a month ago dreamt of entering the Elysee Palace.

Jean-Luc Melenchon, leader of the far left, was returned and promised a "merciless" battle against the government, according to France24. Former prime minister Manuel Vals scraped in, winning his seat by just 139 votes.

But a number of less experienced politicians on Macron's side will help shape France's future.

Mathematician Cedric Villani, known for his bow ties and spider brooches was elected for the seat of Essonne, a Paris suburb.

Mounir Mahjoubi will be the youngest member of government at 33. The son of Moroccan parents, he was previously junior minister for the digital economy.

The second-round vote comes just a month after 39-year-old former banker Macron became the youngest head of state in modern French history, promising to clean up French politics and revive the euro zone's second-biggest economy. His party, LREM, is little more than a year old.

The scale of the majority hands Macron, a pro-European Union centrist, a strong platform from which to make good on campaign promises to revive France's fortunes by cleaning up politics and relaxing regulations that investors say shackle the economy.

Macron cast his vote early in the morning in the seaside resort of Le Touquet before flying to a ceremony outside Paris to mark the anniversary of Charles de Gaulle's 1940 appeal for French resistance to Nazi occupation.

Reform drive

Many of Macron's lawmakers will be political novices, something which will change the face of Parliament at the expense of the conservative and socialist parties which have ruled France for decades.

But he will need to keep the diverse and politically raw group of lawmakers united behind him as he sets out to overhaul the labour code, cut tens of thousands of public sector jobs and overhaul an unwieldy pension system.

Trade unions have said Macron must listen to their demands and not use his majority to bulldoze policy reforms through.

"There has never been such a paradox between a high concentration of power and strong tensions and expectations in terms of changes," Laurent Berger, head of France's CFDT union, told the weekly Journal du Dimanche.

"There is no place for euphoria in victory. There is no providential man, no miracle solution".

Macron's rivals had urged voters not to stay at home, warning power could be too concentrated in the hands of one party and democratic debate stifled.

"We need other parties to have some weight," 54-year-old assembly line worker Veronique Franqueville said on the parking lot of a tumble-dryer factory in the northern town of Amiens. "If he wins it all there will be no debate."

Reuters