French workers at the national rail company, SNCF, have begun strike action against President Nicolas Sarkozy’s plans to reform public-sector pensions.
Workers from other sectors are expected to join them early on Thursday in a one-day protest to pressure Mr Sarkozy to reverse his economic reforms.
Bus drivers nationwide were expected to strike, air service may be disrupted and about 50% of trains are to be cut.
The strikes follow protests by fishermen that blocked French ports.
High-speed international trains between Paris, London and Brussels were not expected to be affected by the SNCF workers’ action.
The transport workers are due to be joined by postal, utility and other public sector workers across France.
The walkouts are not expected to cause the widespread travel chaos of last November when transport workers staged a nine-day strike against Mr Sarkozy’s plan to scrap their special pension rights.
The government and the unions negotiated an end to the strikes but now workers are upset over plans to make them stay on the job one year longer – for 41 years – before receiving a full state pension.
Unions are also upset over government plans to cut the numbers of public sector workers.
Teachers and students have staged a number of strikes and protests over the plans which would see retiring teachers not replaced.
Unions are hoping that a head of steam is building up against Mr Sarkozy’s economic reform plans, says BBC correspondent Hugh Schofield in Paris.
But the president has so far made the calculation that most people accept the changes that he has promised, and there is no sign of him backing down, says our correspondent.
Mr Sarkozy says the reforms are needed to restore France’s economic vitality.
A separate dispute was apparently settled on Wednesday when the French government increased its offer to the fishing industry after days of protests over rising fuel costs.
The fishermen said they were not being adequately compensated to cover their increased costs.
On Wednesday, protesters clashed with police outside the agriculture ministry in central Paris.
Ferry traffic with the UK ground to a halt as fishing fleets blockaded several French ports, causing traffic to back up on English roads to busy ports such as Dover.
The French government offered to accelerate a previous aid deal, paying the fishermen 310m euros (£248m) over two years instead of three.
Pierre-Georges Dachicourt, president of the national fishing committee called on “all fishing crews to return to the sea,” but it was not clear whether fishermen would be satisfied enough to end their stoppage.
And the trouble at the ports may be worsened by a dock workers’ plan to strike on Thursday against privatisation.