Strikes and demonstrations are being organised nationwide in protest at the controversial First Employment Contract (CPE) proposed by Domnique de Villepin, the French prime minister.
The day’s most significant event is expected to be a march attracting tens of thousands in Paris where police have promised to provide extra protection to prevent the muggings and car-burnings that marred the last day of action in the capital on Thursday.
The fifth day of nationwide protests against the CPE is expected to bring much of the country to a standstill, as transport and public sector workers answer union calls for strikes.
The protests have mobilised France’s student bodies and Nicolas Sarkozy, the interior minister, has warned that students taking part in demonstrations could be at risk from gangs from poor city suburbs that were hit by last year's riots.
Police and transport authorities were planning heightened surveillance of trains and buses from the Paris outskirts on Tuesday, and extra forces were to be deployed in side-streets off the route of the march.
However unions opposed police requests to place plain-clothes officers amid the cortege in order to facilitate arrests.
One metro in two will be running in the capital, as well as half of suburban rail links, Paris transport officials said. Bus services will be down in more than 70 towns and cities.
The civil aviation authority DGAC warned passengers to expect delays and cancellations.
Police want to prevent a repeat
of last week's violence
No newspapers will be published on Tuesday and disruption is predicted on state-run radio and television. Schools, post-offices, government offices, unemployment bureaus and some banks could also be hit.
In an increasingly bitter three-week struggle, the government has refused to cede to opposition demands to scrap the CPE, a contract for under 26 year-olds that can be terminated without explanation during a two-year trial period.
Villepin, 52, has staked his political career on winning the showdown with unions, student groups and the political left, who have mounted an escalating campaign of street protests.
According to the government the contract is a vital tool for fighting youth unemployment, which can reach more than 50% in the poor city suburbs, but opponents say it is a breach of hard-won labour rights and will make it more difficult than ever for young people to find long-term jobs.
Some 60 out of 84 universities remained partially or totally shut, with predictions that exams normally taken in May or June may have to be postponed. Many high school students are expected to join Tuesday's protests.
In Thursday's violence gangs of masked youths operating on the fringes of the Paris march attacked property, set fire to cars and mugged passers-by and demonstrating students on the Invalides esplanade. Police made more than 140 arrests.
A union member who was caught in a police baton-charge in a demonstration the previous Saturday remains in a coma.