So says the AA in its latest Fuel Price Report, which shows that between mid-April and mid-May, average petrol prices have risen 1.14p a litre to 136.93. They set a new record of 137.43p last week but a "flash crash" in the oil market, bringing Brent crude down from $125 to below $115, has so far knocked off half a penny.

Diesel prices have fallen even further over the past week. Having returned to the record of 143.04p a litre last Monday, the UK average price of diesel has dropped more than 1.5p to 141.49. A month ago the UK diesel price averaged 141.99p.

The AA says that indications that the average petrol price has further to fall include:

• A 10% fall in the NW Europe wholesale petrol since early May, equivalent to a 4p-a-litre cut that takes into account exchange rate changes,

• Average UK petrol prices were around 133.5p a litre in March when oil hit a plateau of $115 a barrel – before the 1p cut in fuel duty on 23 March.

Edmund King, the AA's president, said: 'Record fuel prices have shaken up shopping patterns – people are beginning to factor in the fuel cost of driving to a large store to shop for basics. This has led to supermarkets trying to find ways to counter that disincentive with cut-price fuel or vouchers. This in turn tightens the pressure on non-supermarket retailers suffering from lower fuel sales.'