There is a campaign, we know where it's coming from: it's Jacques Chirac. The result is I still don't have 500 backers

Jean-Marie Le Pen

Candidates have to present their 500 signatures to the Constitutional Council - one of France's highest courts - between 14 March and 2 April.

Since 1976, all candidates for the French presidency have had to back their bids with 500 signatures from elected officials - local mayors, regional councillors, MPs or senators - from 30 of France's 96 regions.

The founder of the National Front says he still has around 80 names to collect.

"Mayors are receiving letters saying 'Signing for Le Pen is a vote for Jospin'," Mr Le Pen said.

Mr Chirac's spokeswoman Roselyne Bachelot said it would be "regrettable" if anyone was eliminated because of a lack of backers.

She insisted the president's Gaullist party, the RPR, had done nothing to undermine Mr Le Pen.

"You can't eliminate someone who has twice won 4.5 million votes," Mr Le Pen said recently. "You could do that in Managua or Puerto Rico, but not yet in France."

New mood

In previous elections, no serious candidates have had difficulty rounding up backers, but commentators say a new mood prevails among local leaders, who are expressing their broader dissatisfaction with national politics.

Chirac: Le Pen accuses him of political sabotage

"Even the big parties are having difficulty getting mayors to sign up as backers because they're on a sort of strike," said Jean-Louis Borloo, spokesman of the centre-right UDF.

Mr Le Pen is now third in polls of voting intentions, along with Trotskyite veteran Arlette Laguiller, beating former socialist minister Jean-Pierre Chevenement, who was only weeks ago tipped as France's next kingmaker.

In elections in 1988 and 1995, Mr Le Pen's populist anti-immigration stance won him around 15% of the vote.