The Austrian arm of discount supermarkets chain Aldi launched the company's first petrol stations today with astonishingly cheap fuel, triggering hopes that it may do the same in Britain.

Its three trial sites in Austria are selling diesel at only 50 cents a litre and super petrol at just under 60 cents, less than half the normal price in Britain. They are the lowest prices seen on the continent for 30 years.

The launches in Salzburg caused traffic mayhem as motorists came from miles around, even crossing the border from Germany, to fill up.

Police in Salzburg have had to lay on extra patrols to keep the long queues of traffic heading for the pumps on the move.

In Germany the cartel office has already complained that prices for fuel are too high.

The prices spiked this week again as hundreds of thousands of schoolchildren start their holidays and their parents head for the autobahns.

Aldi, which has no public relations or media department, refused to comment about plans to expand.

However, media observers say that testing the waters like this before a major global rollout is typical of its strategy.