France's far-right National Front is set to win more votes than any other party in the first round of local elections next Sunday, a poll showed, with the governing Socialist party coming a very distant third.

The survey by pollster Ifop for Le Figaro daily sees the National Front (FN) scoring 30 percent of the votes. It puts the mainstream conservative UMP — led by ex-President Nicolas Sarkozy — and its center-right UDI ally just behind with 29 percent.

Francois Hollande's Socialists are forecast to win only 19 percent of the vote.

The normally low-key elections in France's departments will this time be scrutinized for signs that Marine Le Pen's FN has gained enough momentum to reach a runoff round in the 2017 presidential election. It came first in French elections to the European Parliament last year.

While the FN is unlikely to get large numbers of its officials elected in the local March 30 runoff, leading in the first round would build on its previous successes.

Hollande's Socialists feared they would lose in the second round but that could happen as early as the first round, Ifop's Jerome Fourquet said, adding that mainstream right-wing parties had been better at crafting pre-election deals.

Adding the scores of smaller right-wing parties would give conservatives another 5 percent in the first round, ahead of the FN.

But while other left-wing and far-left parties would bring the left-wing camp a total score of 33 percent, they would individually score below 10 percent and so are unlikely to make it to the second round, Fourquet said in a note.

The poll carried out March 11-13 suggested a 54 percent abstention rate, as is usual at this election. Less than a third of those surveyed said they could still change their mind.