"Along with workers in France and in Europe, railway workers are sharply hit by exploding inflation, we must act to obtain wage increases," the unions said in a joint statement.

Railway workers are joining a growing number of employees in sectors ranging from oil to airports, air transport and trucking who have called for pay rises to offset the rising cost of living and strikes to back their demands.

The social unrest is piling pressure on French President Emmanuel Macron and his government in the middle of a political crisis, after he and his centrist party lost control of parliament in last Sunday's election. His opponents so far have ruled out any form of coalition or pact with his party.

Workers at TotalEnergies' (TTEF.PA) French oil refineries are striking on Friday. The company said it has taken steps to ensure its network of petrol stations and its clients are sufficiently supplied throughout the weekend.