The national train network and the Paris public transport authority have yet to release details on how service will be affected.

Demonstrations are planned in at least 70 cities and towns throughout France on Tuesday, with the largest march scheduled in Paris, said the CGT union.

Unions say that amid the weak economy, Mr Sarkozy's conservative government has not offered satisfactory plans on jobs, salaries, purchasing power and working conditions.

Unions will also oppose government efforts to reform French pensions.

Teachers are also angry over job cuts and day care employees are opposed to a reorganisation plan.

Meanwhile, President Sarkozy's conservative party was braced for a massive setback in the second round of regional elections as frustrated voters cast ballots in run-off ballots likely to favour the opposition left and to set the stage for the 2012 presidential race.