Villascusa said more than 90,000 drivers are taking part in the strike.

Analysts have estimated that if the transport strike holds, much of Spain will begin to run short of fuel and food by Thursday.

Supply worries

There was almost no movement of lorries early on Monday at Mercamadrid, the main wholesale food market for the Spanish capital.

Long queues formed outside Spanish petrol stations and at some hypermarkets, and truckers say supermarkets will run out of goods within days.

The truckers have put up blockades throughout the country in their call for assistance to cope with a more than a 35 per cent increase in fuel costs this year.

Juan Miguel Sanchez, the development minister, said the government would guarantee market supplies.

Meanwhile, Spanish fishermen are in their second week of protests, also against fuel costs.

At MercaMadrid, the main wholesale food market for Madrid, supplies of domestic fish are drying up, and most of the fish passing through is imported.

Jose Lopez, a fish seller, said: "At the moment it's not noticeable, but tomorrow it is going to start to show [the lack of fish]."