Just ten per cent of more than 4,500 UK forecourts are charging a fair price for petrol and diesel, according to new figures from the RAC.

The breakdown assistance firm believes that retailers should be charging nearer to 174p for a litre of unleaded in response to wholesale prices that have continued to fall over the last two weeks. Despite this, analysis shows that only 157 petrol stations – out of 4,593 sites included in the study – were selling a litre between 170.9p and 179.9p.

RAC fuel spokesman Simon Williams said: “In this most expensive of summers, drivers need all the help they can get to keep their spending down so we applaud those retailers who are doing the right thing for their customers and charging a fair price for petrol and diesel, more in line with the lower wholesale costs.

“Weekly wholesale petrol prices – that’s the price retailers pay to buy the fuel – have fallen by a massive 17p a litre, from a weekly average of around 152p at the start of June to just 135p this week. Yet average pump prices have reduced by a paltry 4p. It’s time for every retailer to do the right thing and cut their prices to more reasonable levels.”

Williams added: ​​“Last month, the cost of filling a typical 55-litre family-sized car with petrol rose by a record £9.12, with diesel just behind at £8.59. For a car that does 40 miles to the gallon, that means it costs a driver around 22p for every mile they drive – up from around 16p at the start of the year. Drivers are desperate for some relief at the pumps yet, with a few notable exceptions, few retailers seem to be willing to price their fuel fairly.

“Drivers who fill up at supermarket forecourts have every right to feel let down that they are being charged well over the odds for petrol and diesel right now.”