French unions and student groups have called for fresh strikes and protests next week to keep up the pressure on the government over the youth job law.
More than a million people have joined the protests
Universities across the country have been disrupted for weeks by protests over the law, which makes it easier for employers to fire first-time workers.
Hundreds have been arrested in violent clashes with police amid generally peaceful protests.
PM Dominique de Villepin has refused to back down, saying the law creates jobs.
He has said he is waiting for the verdict of the French Constitutional Council, which on Thursday is expected to rule on an appeal against the First Employment Contract, or CPE as it is known.
If the council declares the law is compatible with the constitution, French President Jacques Chirac will have 15 days in which to pass the law or ask parliament to review it.
The alliance of trade unions and students, whose demonstrations attracted more than one million protesters on Tuesday, called for a repeat show of support on 4 April.
The unions have urged President Jacques Chirac to use his powers and block the controversial law.
VIEWS ON THE STREETS
Opponents and supporters of the CPE air their views
Mr Chirac's office said the president would speak on the issue "in the coming days".
Mr de Villepin remains the man at the centre of this storm - determined to ride it out, but caught between forces that are proving impossible to control, says the BBC's Caroline Wyatt in Paris.
On one side is the anger on the streets and the fear that this violence will set the suburbs alight again, she says, but pushing him the other way is his desire to be the strong man who reformed France - where all his predecessors failed.
On Friday, Mr de Villepin was forced to defend himself again at a session in parliament during which opposition MPs jeered him when he made a Freudian slip of the tongue, our correspondent says.
The prime minister responded to their calls for him to stand down by using the word resignation - instead of decision - when referring to the constitutional council that is to rule on the legality of the new contracts, our correspondent says.
FRENCH STUDENT PROTESTS
2005: Conservative education minister withdraws key elements of school reform after pupils and teachers protest
1995: Protests over pension reforms push conservative PM Alain Juppe from office two years later
1994: Conservative PM Edouard Balladur abandons law cutting wages for young people in job training in face of month of protests
1986: Conservative government shelves plan to implement university reform in face of mass protest
May 1968: Uprisings help undermine legitimacy of President Charles de Gaulle, who stands down following year
Protesters are bitterly opposed to the CPE, which allows employers to end job contracts for workers under 26 at any time during a two-year trial period without having to offer an explanation.
Mr de Villepin has said he was open to talks on employment and possible changes to the contracts, but he did not say he would withdraw them.
The government says the law will encourage employers to hire young people, but students fear it will erode job stability in a country where more than 20% of 18-to-25-year-olds are unemployed - more than twice the national average.