FairFuelUK has accused fuel retailers of 'fleecing' motorists after its research showed pump prices were not falling in line with wholesale costs.

The organisation found that since mid-March, the price of wholesale diesel has averaged four pence per litre less than petrol while the retail price between the two fuels has remained the same.

It also reported that thousands of garages are selling diesel at more than the price of petrol despite diesel’s persistent lower wholesale price.

Howard Cox, founder of the FairFuelUK Campaign said: “Wholesale petrol has been 5p higher than diesel for weeks and yet pump prices remain the same for both fuels.

"It’s clear following the Budget’s continuing freeze in duty due largely to our hard scrapped campaigning, those in the fuel supply chain are now returning to type.

"To unscrupulously fleece motorists, particularly those that fill up with diesel.

“Retailers are not passing on the benefits of lower oil prices revealed in current wholesale levels and in some cases are now taking a huge 12p per litre in margins.

"That’s £5 profit from an average motorist each time they fill up.

"FairFuelUK supporters are already livid they are paying the highest fuel tax in the EU but this persistent profiteering by retailers, and their manipulative rocket and feather pricing tactics is making UK drivers even more incandescent with rage.”