PARIS - French voters gave newly elected President Nicolas Sarkozy's party the lead Sunday in the first round of legislative elections.

Sarkozy's rightist UMP party won 39.6 per cent of the vote, while the opposition Socialists had 24.7 per cent, the Interior Ministry said.

Sarkozy's party has a strong advantage heading into the decisive runoff next Sunday, on track to expand their absolute majority in the 577-seat legislature. Control of the National Assembly is central to Sarkozy's agenda of tax cuts, labour legislation and other plans.

The election sapped support from the fringes -- including Jean-Marie Le Pen's once-influential neo-fascist National Front and the Socialists' farther-left allies -- and leaves France facing a legislature tilted well to the right.

Turnout was less than 61 per cent -- low for France -- which pollsters blamed on a lack of suspense. The UMP has been widely expected to win since Sarkozy's strong victory over Socialist Segolene Royal in the presidential election last month. The main question was how badly the once-powerful leftists would lose.

Socialists tried to rally backing for the second round, tapping fears of an all-powerful "Sarko state'' if the president's camp wins a lopsided majority.

"There are crushing majorities that crush, dominant parties that dominate, absolute powers that govern absolutely,'' Socialist leader Francois Hollande said.

Sarkozy's backers say a convincing mandate is the only way to force the French, eager to strike and wary of globalization, to change.

"We want to set off a shockwave of confidence, a shockwave of growth,'' a buoyant Prime Minister Francois Fillon said Sunday night.

He laid out his agenda for change for the summer and autumn: reform of universities, making transport strikes less crippling, new anti-crime measures, freeing up the labour market and a plan to cut the large national debt.

Many outside the conservatives' circle dread the months to come.

Labor unions and student groups stand ready to resist with the kind of mass protests that logjammed reforms by former president Jacques Chirac.

Francois Bayrou, the third-place finisher in the presidential vote, warned of a "terribly'' one-sided legislature.

"One day, France will regret this lack of balance. It is not healthy,'' said Bayrou.

His fledgling new party MoDem won 7.6 per cent.

The Socialists' downfall may send the party soul-searching about its direction in an era when many European leftists have moved to the centre and come to terms with global capital markets.

Polling agencies TNS, Ipsos and CSA concurred the UMP would expand its majority, but varied widely in projecting how many seats they would win: they predicted between 383 and 501 for the UMP and other mainstream right groups and between 69 and 185 seats for the Socialists and other leftist parties.

In the current legislature, the UMP has 359 seats and the Socialists 149.

The National Front, which played the kingmaker in elections past and won 15 per cent in 1997, won just over four per cent this time -- and not a single seat.

The Communists, who held 86 seats in the 1970s, are projected to win no more than 12 this time. The party's struggle for workers' rights has had substantial influence on French politics for many years.

The parliamentary election marked a milestone in modern French politics: voters look set to return the outgoing majority to power for the first time since 1978.

Any candidate who wins more than 50 per cent of the vote lands a seat. In most cases there is no immediate winner, so all candidates with more than 12.5 per cent of the vote go to the runoff.

A total of 7,639 candidates from 14 parties are vying for five-year terms in the assembly.

The interior minister said at least 53 candidates -- all from Sarkozy's camp -- won by an absolute majority in the first round.