Hundreds of thousands of people are expected to take part in a national strike in France tomorrow which will further test Prime Minister Dominique de Villepin controversial youth job contract.
Commuters face travel chaos, with rail workers launching a 36-hour stoppage tonight. Air travel was also likely to be hit.
Mr de Villepin's proposal would mean under 26s have lesser employment rights under the terms of the CPE contract.
Unions said 135 demonstrations were planned to protest against a contract which critics say will create a generation of "throwaway workers" and fail to cut high youth unemployment.
"We hope that after the protests the government ... withdraws the text," said the opposition Socialist party's spokesman, Julien Dray. "There is no other solution."
Mr de Villepin, who faces the biggest test of his 300 days in office, invited unions and student bodies to meet him on Wednesday to find common ground. He offered to discuss the two-year trial period and how employers can fire young workers.
But he has so far refused to withdraw the CPE even though there is no sign the protests are waning after flaring earlier this month.
Business groups have warned the government the economy could be damaged by the protests.
Fears of a broader revolt have been fuelled by incidents in Paris last week including looting, clashes with riot police and the mugging of student demonstrators by hardcore elements.
Unemployment stands at 9.6 per cent of the workforce and at 23 per cent among young people.
There is broad agreement on the need to reduce unemployment but a consensus on the method is proving illusive.