France's embattled Socialist government faced a no-confidence vote Thursday after bypassing parliament to force through a labour reform bill that once again drew thousands onto the streets in protest.
Unions and student groups marched in Paris and other cities including Marseille, Nantes and Toulouse, as they have done regularly since the government proposed the reform two months ago.
Violence broke out at one protest in the capital when masked youths clashed with demonstrators and journalists. Riot police had left the scene shortly beforehand.
The CGT union said 50,000 people demonstrated in Paris.
The government says the reform is aimed at loosening up France's notoriously rigid job market.
But protesting students who believe it is weighed in favour of businesses unfurled a banner reading "Medef (the employers' federation) commands, the government obeys, the youth resist".
The government's decision Tuesday to force through the adoption of the reform has been widely seen as an admission of failure as the deeply unpopular President Francois Hollande grapples with a decision over whether to seek re-election.
The move also laid bare a gaping rift in the Socialist Party as rebel MPs had threatened to doom the legislation in parliament.
On the right, meanwhile, the reform is seen as too timid -- mocked as "a shadow of its former self" -- after waves of angry street protests forced the government to make a number of concessions.
Opponents need 288 votes to bring down the government, which is considered highly unlikely because Socialist rebels and Green lawmakers have said they will refuse to back the opposition motion.
The rebel Socialist MPs failed by just two votes to bring their own vote of no confidence, but their efforts drew a stern warning from the parliamentary relations minister, Jean-Marie Le Guen, who said Thursday that they had "gone too far".
Prime Minister Manuel Valls was defiant, saying Wednesday the reform must go ahead "because the country must move forward and because salary negotiations and workers' rights must progress."
The government argues that the reform will give companies more flexibility to fight endemic unemployment.
Joblessness, which stands at 10 percent overall and at nearly 25 percent for young people, has plagued Hollande's four years in power.
The right, which has a minority in the National Assembly, or lower house, says Hollande has led France into an "impasse".
Paradoxically, the motion will receive support from the far-left Front de Gauche party, which said Thursday its goal was not to bring down the government but to torpedo the reform.
"The only tool we have left, the only leverage, is the no-confidence vote," said the party's parliamentary group leader Andre Chassaigne.
The standoff over the labour reform is just the latest headache for Hollande since he was forced to abandon his attempts at changing the constitution in the wake of the November 13 terror attacks on Paris.
In a sign of the government's nervousness on the labour reform issue, it has made a significant U-turn on one of the most controversial measures. Companies that want to lay off staff will not be able to point solely to losses in France to justify such a move.
Unions fear that companies with profitable international operations will "cook the books" to make it look as if their French units are making a loss, in order to trim their work forces.
All of this comes less than a year from the 2017 presidential election.
Hollande, facing some of the lowest popularity scores of any left-wing French president, has said he will decide by the end of the year whether to stand for re-election.
Fresh protests are set for Saturday, with student leader William Martinet warning: "The government will not succeed in silencing young people."
CGT leader Philippe Martinez called for demonstrations to "switch into a higher gear", telling the far-left daily Humanite: "Workers seem to have decided to commit to a hardline movement."