The race in the posh Paris suburb of Neuilly-sur-Seine - where Mr Sarkozy long served as mayor - has shaped up as a test for the president, whose poll numbers have fallen recently and whose once-hearty appetite for reform has shrunk.

The elections in around 36,000 French cities, towns and villages are the first nationwide polls since Mr Sarkozy was elected president last May - and some in his conservative UMP party fear its candidates will be punished by voters who are disappointed with Mr Sarkozy.

In one of the most high-profile races, Sarkozy had supported his presidential spokesman, Mr David Martinon, as the party's top candidate in Neuilly. Mr Jean Sarkozy, 21, the second of the president's three sons, had often been on the campaign trail alongside Mr Martinon.

But after Le Figaro daily reported on Saturday that a 'confidential' poll there showed Mr Martinon was trailing behind another conservative, a cloud of doubt has swirled about the spokesman's candidacy.

Mr Jean Sarkozy and two political allies said on Sunday that they were breaking ranks with Mr Martinon - who has faced criticism because he only recently moved to Neuilly - and forming their own list of candidates for mayor and city council. They did not specify who would head the list as the mayoral hopeful.

Neuilly 'asks for people who are deeply attached to it, that it knows, in whom it has confidence,' Mr Jean Sarkozy told reporters in the city's centre.

'The party's rank-and-file want us to assume our responsibilities,' he said, 'and when they see that we're headed straight into a wall, they ask us to keep an eye on the trajectory.'

No reasons specified for split
Mr Jean Sarkozy did not specify the reasons for the rupture with Mr Martinon, and declined to comment when asked about the role played in the decision of his father, who was mayor here from 1983 to 2002.

But it was highly unlikely that the president was unaware of the political mutiny involving his son.

'I recognise that there's a bit of confusion today. That's the least we can say,' UMP secretary-general Patrick Devedjian said on France-2 television. He said local party leaders would meet on Monday to clarify their candidate slate.

The president's office declined immediate comment. Mr Martinon, who had been expected to canvass on Sunday at a Neuilly market, called off the planned appearance and declined to speak to reporters. In a text message to The Associated Press, Mr Martinon said he would not join Mr Sarkozy's entourage for a trip late Sunday to French Guiana, as had been originally planned.

Mr Francois Bayrou, a centre-right lawmaker who ran and lost against Mr Sarkozy in the election last year, told reporters in Paris the disavowal of Mr Martinon smacked of 'royal court' intrigue - and criticized Mr Sarkozy's way of blurring his family life with his political activities.

Mr Sarkozy's poll numbers have dwindled over the last few months , jeopardising his reforms. The government last week backed off a plan to increase the number of taxi driver licenses - part of efforts to create jobs - after strikes by cab drivers out of fear of new competition.

Nearly two-thirds of the members of Mr Sarkozy's Cabinet are standing for the municipal election. In France, it is not unusual for government ministers to simultaneously serve in elected positions such as mayor or lawmaker.

Prime Minister Francois Fillon, Interior Minister Michele Alliot-Marie, Defence Minister Herve Morin, and Justice Minister Rachida Dati are among candidates. The elections take place March 9 and March 16. -- AP