Sales of diesel-powered cars are expected to slow, as the average price of diesel at the end of June reached 132.27p per litre - 22.5% higher than it was at the beginning of the year.

Kirk Fletcher, managing director of Experian’s Automotive division, said: “If diesel fuel prices continue to rise at this rate, we may see a slow down in the sale of diesel cars and a bigger shift over to cars that are running on alternative fuel.

"We are already seeing a rapid increase in the sale of hybrid cars, which were up by 93% during the first quarter of 2008 compared to the same period in 2007, and electric cars which increased by 415%.”