France could force foreign trucks to take the country's toll motorways - instead of using the corresponding A-road itineraries, when these exist - as an alternative to its HGV tax scheme which was postponed last autumn amid growing opposition.

The proposals have been roundly criticised in Brussels with a spokesperson for European Transport commissioner Siim Kallas, underlining that it was impossible to put in place "a discriminatory system" between French and foreign hauliers.

Undeterred, new French Ecology and Sustainable Development minister, Segolene Royal, argues that, on the contrary, they would re-establish fair competition.

"When a foreign truck enters France, having filled its tank in Belgium, crosses the whole of the country, using roads paid for by French taxpayers and subsequently fills up again in Spain, it is not paying any taxes on fuel or motorway tolls. In effect, French trucks are paying for the upkeep of the roads. One must make everyone pay, especially those who today don't contribute anything."

The proceeds generated by a greater number of foreign trucks using toll motorways would be reserved for the funding of transport infrastructure, she added.

Since 1 April, foreign hauliers are now charged to use UK roads through a HGV road user levy.

This was introduced to counterbalance the costs incurred by UK truck drivers working in Europe in the form of tolls and levies when delivering goods abroad.

Separately, at a European conference in Paris last week, French Transport minister, Frederic Cuvillier, called for the creation of an EU Transport Agency, part of whose role would be to ensure better supervision of the regulatory framework for road haulage.

The conference had discussed the harmonisation of labour legislation in the sector in the EU.

"There can only be an internal market in the EU if there are controls to ensure its laws are being respected," Cuvillier said.