Official campaigning has begun in France's presidential election ahead of first round polling on 22 April.
Polls show Mr Sarkozy still ahead of the Socialists' Segolene Royal
Twelve candidates are vying to succeed veteran centre-right leader Jacques Chirac, 74, who is stepping down.
Nicolas Sarkozy of the centre-right UMP remains the frontrunner, with Socialist rival Segolene Royal in second place.
Polls show centrist candidate Francois Bayrou not far behind, with far-right leader Jean-Marie Le Pen - who reached the second round in 2002 - fourth.
The anti-globalisation farmer Jose Bove kicked off the campaign with a five-minute television broadcast calling for a more radical left-wing agenda in a France "faced with a flabby left and a hardline right".
Equal air time
Early on Monday, election posters went up outside the 85,000 polling stations across France.
Candidates are accorded strict equality in terms of air time on radio and television.
Each one has 45 minutes of broadcast time. They can use three types of campaign clip: one-minute, two-and-a-half minutes and five-and-a-half minutes.
The election is expected to go to a second round between the two leading candidates on 6 May, as no candidate is considered likely to win 50% or more of the vote on 22 April.
A survey by CSA in Le Parisien newspaper on Sunday indicated that 42% of voters were still undecided.
Segolene Royal has tried to rally Socialist core voters
A CSA official said that was 10 points higher than at the same stage in 2002.
The latest opinion poll by Ifop shows Mr Sarkozy winning the second round with 54%, compared with Ms Royal's 46%.
In the first round, Mr Sarkozy is credited with 29.5%, Ms Royal with 22%, Mr Bayrou with 19% and Mr Le Pen with 14%, according to Ifop.
Election officials say record numbers of people - more than 44.5 million - have registered to vote.
Experts say the sudden political fervour has been prompted by anxiety, because many French people were frightened by the last elections when Mr Le Pen came second, reports the BBC's Emma-Jane Kirby.