A resounding Socialist victory in parliamentary elections will allow President Francois Hollande to press ahead with reforms to tame France's deficit and promote economic growth in Europe.

The Socialist Party and its affiliates secured 307 seats, more than the 289 needed for a majority in the 577-seat National Assembly.

The left-wing triumph means Mr Hollande, will not need to rely on the Greens, who won 16 seats, or the Communist-dominated Left Front, with 10 deputies, to pass laws.

The centre-left already controls the upper house of parliament, the Senate.

Finance Minister Pierre Moscovici called the result a vote of confidence in Mr Hollande's government that would enable it to forge ahead with its economic and eurozone policies.

"Europe's future is at stake in the weeks ahead," he said.

The mainstream conservatives, who oppose Mr Hollande's plans to raise taxes on the rich, won 224 seats.

The far-right achieved a breakthrough, winning three seats and giving the National Front a voice in parliament for the first time since the mid-1980s.

The anti-euro presidential campaign by party leader Marine Le Pen struck a chord in a nation struggling with 10% unemployment.

Ms Le Pen narrowly lost her race in a working-class northern town, but her 22-year-old niece, Marion Marechal Le Pen, granddaughter of the anti-immigrant party's founder Jean-Marie Le Pen, was elected in the southern town of Carpentras.

Lawyer Gilbert Collard, a non-member who was chairman of Marine Le Pen's support committee, and estranged former party member Jacques Bompard won the other two seats in the south.

The leftward swing gives the Socialists more power than they have ever held as Hollande pushes for new tools to stimulate growth in the eurozone and a European banking union that would protect depositors and states if banks fail.

The Socialist leader flies to Mexico today for a G20 summit that will be dominated by the eurozone's woes as a rift with the bloc's paymaster Germany over how to resolve the crisis has sparked a rare public squabble.