Supermarkets are being urged to cut their fuel prices by 5p a litre as new analysis shows they are charging “excessive” margins.

While Asda is still the cheapest of the big four, the RAC says it seems less keen to lower prices in a falling wholesale market than it has been in the past

RAC data reveals supermarkets are currently enjoying margins of around 15p a litre on both petrol and diesel. This is leaving hard-pressed drivers having to fork out for petrol at an “unnecessarily high” average price of 160.96p and 184.41p for diesel – only 2p lower than the UK average of 163.24p for unleaded and 3p lower for diesel (187.42p).

A lower average margin of 10p a litre on both fuels would bring petrol prices down to 152p and 173p for diesel – around 9p and 11p less that currently.

While wholesale fuel prices have reduced significantly since mid-October, supermarkets haven’t been reducing their forecourt prices to the same extent.

RAC fuel spokesman Simon Williams said: “With many people struggling to put fuel in their cars it’s very sad to see the biggest fuel retailers taking advantage of their customers by charging far higher prices than they should be. This is unfortunately a perfect example of prices falling like a feather, the opposite of them rocketing up as soon as the wholesale price rises significantly.”

He added that while supermarkets had traditionally sold petrol and diesel at lower prices due to the large volumes they sell, there was now a “remarkable” lack of competition among the four main players which means prices are far higher than they should be.

“If one of the supermarkets were to lead a round of price cuts, the others would follow suit which, in turn, would bring the average price of fuel down for the benefit of drivers everywhere.

“Asda has traditionally been the most aggressive supermarket on fuel prices, but while it’s still the cheapest of the big four, it seems far less keen to lower prices in a falling wholesale market than it has been in the past.”

And while the RAC has urged supermarkets to do the right thing by their customers and cut prices by at least 5p a litre immediately, it’s warned that drivers could be in for some pre-Christmas disappointment. Despite similar margins in 2021 the supermarkets failed to cut their prices significantly.

Drivers are also being reminded there are smaller, independent forecourts offering more competitive prices than supermarkets – so it remains best to shop around.