Former president Nicolas Sarkozy's conservative UMP party and their allies lead in the first round of French local elections, according to a TV exit poll, denying Marine Le Pen's far-right National Front (FN) first place.

If confirmed the result would be a setback for Ms Le Pen, who had hoped her anti-immigrant, anti-euro party would emerge top in the first round, boosting her ambitions to win presidential elections set for 2017.

The UMP and its partners together secured 29.2% of the vote nationally, ahead of the anti-immigrant, anti-euro FN on 26.3%.

As expected, President Francois Hollande's ruling Socialists came third in the mid-term election with just 21.4% of the vote.

Seats in more than 100 regions, or departments, are being contested.

Opinion polls had suggested voters are unexcited about the election for councillors with limited powers, which Mr Hollande has promised to overhaul.

However, by 5pm local time (4pm Irish time), three hours before polling stations closed, official figures showed participation had reached about 43%, more than six points higher than at the same stage on the equivalent polling day four years ago and indicating a higher final voting rate than had been expected.

Three exit polls put the final participation rate at between 50.5% and 51.5%, against a pre-election poll of 47% on Friday and compared with 44.3% participation in 2011.

For the National Front, today is a chance to punish the Socialists and get up a head of steam for presidential elections in 2017 that some analysts believe could see the party's leader Marine Le Pen oust the unpopular Mr Hollande.

"We'll get stuck into the regions and then we're off to invade the Elysee (presidential palace)," Ms Le Pen declared this week.