The Competition and Markets Authority (CMA) has found that average supermarket fuel margins rose by 6p per litre between 2019 and 2022.
Motorists paid an extra £900 million on fuel thanks to the rise in costs at Asda, Tesco, Sainsbury’s and Morrisons.
The CMA inquiry also found that diesel owners paid an extra 13p per litre during the first five months of the year, thanks to increasing margins.
In response to the unfairly high prices, the Government has said it will introduce a law forcing fuel retailers to make their up-to-date pricing information available to third parties.
This will potentially lead to the creation of fuel price comparison apps and websites, allowing drivers to find the cheapest fuel prices in their area.
The Government have also said that they plan to hand this over to a public organisation to ‘closely monitor’ pump prices and alert ministers if further intervention regarding fuel prices is needed. The plan is set to launch in autumn.
CMA chief executive Sarah Cardell pointed out that the costs “will have had a greater impact on vulnerable people, particularly those in areas with less choice of fuel stations.”
“We need to reignite competition among fuel retailers”, she added.
Energy Security Secretary Grant Shapps said: “Some fuel retailers have been using motorists as cash cows. They jacked up their prices when fuel costs rocketed but failed to pass on savings now costs have fallen.
“It cannot be right that at a time when families are struggling with rising living costs, retailers are prioritising their bottom line, putting upwards pressure on inflation and pocketing hundreds of millions of pounds at the expense of hardworking people.”
Chancellor Jeremy Hunt said: “It isn’t fair that businesses are refusing to pass on lower prices to protect their profits while working people struggle with balancing their budgets.”
“Consumers need to be treated fairly, and so we’re empowering drivers to find the best prices possible for their fuel by taking swift steps following the CMA’s recommendations.”
The RAC said it is “extremely pleased” that the Government is taking action.