Tens of thousands of French workers took to the streets on Thursday as unions mounted a one-day show of force against President Nicolas Sarkozy's government over pension reforms.

Fishermen, dock and ports workers demonstrate over pension reforms with public sector workers in Marseille, southern France, May 22, 2008. French unions staged nationwide protests on Thursday against plans by President Nicolas Sarkozy to make people work longer to qualify for a full pension. [Agencies]

Major queues of trucks also built up at the Channel port of Calais because of a strike against dock privatization plans.

Rail workers led the national stoppage, with only half of trains running across France, as public sector workers join some 80 protest rallies planned across the country.

But expected rush-hour chaos was limited in Paris and other major cities, as the unions stuck to new rules on running a minimum service during strikes.

Unions hoped to draw half a million people into the streets, with six in 10 French people saying they support the movement, according to a poll in Liberation newspaper.

Between 40,000 protestors, according to police, and 150,000 according to unions turned for early protests in Nantes, Rouen and Le Havre in the west, Grenoble and Marseille the southeast and Clermont-Ferrand in the centre.