President Chirac called for trade union and student marches, which unions expect to draw up to 1.5 million people, to take place in a climate of “calm and respect for all” and for negotiations to begin “as soon as possible”.
Security has been tightened ahead of the main afternoon march in Paris, to avoid a repeat of the violence that saw 300 people arrested at the end of student protests.
Thousands of police officers are under instructions to identify and isolate “professional troublemakers” from the rest of the protestors.
Surveillance was also to be stepped up in Paris’ suburbs, with orders to arrest individuals suspected of planning violent action in the city centre.
Between 250,000 and half a million people marched across France on Thursday in a show of force over a new youth job contract, denounced as a licence to hire and fire at will by students, unions and the left-wing opposition.
Police later arrested 187 people in central Paris, where hundreds of youths, described as outside troublemakers, fought running battles with police.
More than 90 police officers and 18 demonstrators were injured in clashes in Paris and in the northern city of Rennes, where police made 19 arrests.
Interior Minister Nicolas Sarkozy blamed the violence on “thugs” and “hooligans” from the far-left and far-right, as well as young delinquents from the Paris suburbs, who he said had infiltrated the march in the capital.
Several far-right youth leaders were arrested in the Paris violence, including the head of the Youth National Front, and members of a banned group linked to an attempt on Chirac’s life in 2002, according to a police official.
In the Paris suburbs, incidents of vandalism were reported on the sidelines of several high-school protests on Friday and police arrested a dozen youths in the town of Raincy, who were trying to block a railway line with metal bars.
Several hundred youths hurled stones at a high-school in the tough suburb of La Courneuve, and in nearby Bobigny the town hall was closed after several dozen youths tried to storm it with metal barriers.
Prime Minister Dominique de Villepin championed the First Employment Contract (CPE) as a solution to youth unemployment, which affects one in four French youths, and hits 50 percent in some of the suburbs hit by rioting last year.
Opponents of the CPE, a first job contract for under-26-year-olds which can be broken off without explanation in the first two years, say it will entrench job insecurity among the young.
President Chirac repeated his defence of the scheme, saying it was an “important element in fighting unemployment” and would “create new jobs for young people who are largely left by the wayside in the jobs market”.