PARIS (REUTERS) - Several thousand truck drivers blocked roads across France on Saturday, causing severe disruption to traffic in protest against a new environmental tax on heavy goods vehicles.

The protest is the latest effort to force the French government to cancel the so-called "ecotax" through which it aims to raise more than 1 billion euros (S$1.7 billion) a year to finance mostly rail infrastructure projects.

There was significant disruption all over the country, from the Paris region to Bordeaux and Aix-en-Provence in the south, affecting transit towards Spain and Italy.

On the main highways, truck drivers let cars through but blocked foreign trucks, forcing them to stand idle on the side of the road.

In reaction to protests against the tax, the French government has suspended its implementation ahead of an original Jan 1 implementation date, but protesters said they would not give up until the tax was scrapped altogether.

"Until this measure is cancelled, we will remain mobilised," said Mr Vincent Tardet from the European Rail Transport Organisation (OTRE) which set up some 26 blockades on France's main road arteries.

The organisation said 4,500 trucks took part in the protest on Saturday while the French ministry of interior put the number at 2,200. The protest was due to end at 1800 GMT (1am Singapore time).

President Francois Hollande's government, struggling to bring down the public deficit while protecting a fragile economic recovery ahead of municipal and European elections next year, has also backtracked on plans to increase tax on some savings products.