Thousands of commuters across France were left stranded

The strikes are the first since French voters firmly rejected the proposed EU constitution in a referendum on Sunday.

The "No" vote triggered a change of prime minister. Dominique de Villepin is to announce his new team soon.

Trade unions, who had campaigned for a "No" vote, are protesting against job cuts in France's state-run railways.

Thursday's strikes are seen as a show of strength, as President Jacques Chirac and Prime Minister de Villepin grapple with the major political crisis unleashed by the referendum.

Public sector anxiety

More than half the train services were cancelled in the Paris area, leaving thousands stranded.

Villepin and Chirac are charting a course into an uncertain future

At least 25% of train staff were on strike across the country.

The head of the Force Ouvriere trade union, Jean-Claude Mailly, said its members were defending an "idea that public service workers are attached to".

He added that this demand was also behind their vote on Sunday.

Fifty-five percent of French people rejected the EU constitution - in a vote that was also interpreted as a rejection of the government's economic record.

Mr Chirac said he had "taken note" of the people's message, and promised action to create more jobs.