President Sarkozy's private life has been headline news
President Nicolas Sarkozy's ruling UMP conservative party is trailing in the first round of French local elections.
Early results, based on a count of 65.7% of votes, put the UMP at 45.5% with the opposition socialists at 47%.
The vote is seen as a test of Mr Sarkozy's first year in office. His popularity has fallen in recent months.
However, the socialists' lead is smaller than some predicted, and the outcome in some large cities in particular remains finely balanced.
Socialist leader Francois Hollande said voters had sent a warning to Mr Sarkozy and the government over its policies.
The Socialists are expected to hold on to power in Paris and Lyon and exit polls suggested they could also take Marseille, Strasbourg and Toulouse from Mr Sarkozy's party.
But although UMP head Patrick Devedjian admitted earlier that the results were "not good", another conservative said there had been no "pink wave" - meaning no surge of left-wing support across the country.
The second round run-off is scheduled for 16 March.
The BBC's Alasdair Sandford in Paris says that the vote is being seen as one of disapproval over Mr Sarkozy's first 10 months in power.
Many French people have complained that promised reforms have failed to improve their standard of living, while the president's high-profile private life raised concerns among some that he was neglecting his public duties, our correspondent says.
In an interview with Le Figaro newspaper on Thursday, Mr Sarkozy played down the expected UMP losses.
"The crucial date for me is the end of my term" in 2012, he said.
He has insisted there will be no cabinet reshuffle, and that his reform programme will go ahead regardless.
The president's approval ratings reached 67% in July last year.
But recent opinion polls suggest up to two-thirds of French voters now disapprove of his policies.