Drivers are being warned thatthe latest rise in crude oil prices to record highs could add another 20p to a litre at the pumps.

The forecast, from the Institute of Advanced Motorists (IAM), came as new figures showed car sales falling in the face of high fuel prices and collapsing consumer confidence.

Fuel prices set yet another record yesterday at the pumps, rising to a national average of 119p for unleaded and 132.4p for diesel, according to the IAM Motoring Trust, which monitors pump prices daily.

IAM's technical director, Tim Shallcross, said the surge in oil prices in recent days to fresh records above $146 a barrel had yet to feed through to the pumps.

"If crude prices stay around their current level, we could well see another 20p on a litre over the coming month," he said.

Crude prices retreated by around a dollar a barrel yesterday but were still just under $145 a barrel, with many predicting they will soon push above $150.

Mr Shallcross said that petrol retailers had not passed on the full cost of the 100 per cent rise in crude prices over the 12 months to the end of June.

If they had, he said, unleaded would already be at 140p a litre on average and diesel 150p.