The price of diesel and petrol at UK filling stations came down during May, according to the RAC.

The motoring organisation said the cost of the average litre of diesel fell by 4.5p, to 153.58p, while the average litre of petrol reduced by 2.4p, to 147.88p.

However, the RAC said prices should have come down further, with retailers currently taking bigger margins than had historically been the case, at 13p for petrol and 16p for diesel, versus around 8p for both fuels previously.

RAC senior policy officer Rod Dennis said: “A month of decreasing fuel prices should be seen as a good one for drivers, but the sheer time it is taking for any meaningful price reductions to reach forecourts is if anything a continuing cause of concern. 

“When it comes to much-needed pump price cuts, it’s sadly a case of too little, too leisurely, with most drivers still getting a miserable deal every time they fill up.

“We’re once again in classic ‘rocket and feather’ territory, with pump prices only trickling down when they should really be falling like a stone. What’s more, not only have wholesale prices been coming down consistently for over a month, but the average margins taken by retailers are still so much bigger than in the past.

“This means pump prices are at levels much higher than we ought to be seeing, which is all the more concerning given drivers are meant to still be benefiting from a 5p a litre duty cut introduced more than two years ago.”