Far-right leader Jean Marie Le Pen accused rivals today of trying to freeze him out of the French presidential election.
A number of other hopefuls also risk being shut out after mainstream parties combined to try to prevent a repeat of the 2002 election when Mr Le Pen beat then-Socialist Prime Minister Lionel Jospin into third place.
Under electoral law, a politician needs the sponsorship of at least 500 of France's 42,000 elected representatives, including parliamentarians and mayors, to become a candidate.
The signatures have to be collected by March 16th, and Mr Le Pen said he was still 100 short. "We are faced by a broad and very well-prepared offensive to try to persuade mayors not to sign our (sponsorship) promises," he said, indicating he suspected a mole might have leaked the names of his potential backers.
A record 16 presidential hopefuls contested the election four years ago, diluting the vote for bigger parties and helping push a stunned Mr Jospin out of the second round of the ballot.
This time around, just five candidates say they have collected the necessary signatures, leaving dozens of other pretenders scrambling for support.
The Socialists and ruling UMP party have ordered their own mayors not to sponsor rivals, and independent officials say they face huge pressure to shun extremists of any kind.
Despite Mr Le Pen's success in 2002, when he won 16.8 per cent of the vote, his National Front party does not have any mayor,s and he has criss-crossed France for months to find backers.
Mr Le Pen accused a far-right rival, Philippe de Villiers, of trying to poach his backers and said he would sue. Villiers, who is at least 40 signatures short, called the accusation pathetic.
Sponsorship does not necessarily mean the mayors support a candidate but simply that they consider he or she represents a legitimate current of public opinion.