The average price of petrol and diesel at UK filling stations fell in December, according to data from the RAC.

The motoring organisation said the average litre of petrol fell by 6p during the month, to 140.58p, while the average litre of diesel fell by 5p, to 149.18p.

The RAC said the price of petrol had now fallen to a level last seen in early February 2022, before Russia’s invasion of Ukraine.

However, it has argued prices should be lower still, citing lower prices in Northern Ireland than the rest of the UK, and blaming supermarket fuel margins, which it says are more than double those taken in 2021.

RAC spokesman Simon Williams said: “It’s clearly good news that both petrol and diesel came down substantially in December. While we’re starting the year paying much less at the pumps than we have done, it’s still galling to know that drivers aren’t being charged a fair price in comparison to Northern Ireland where the very same petrol and diesel is at least 5p a litre cheaper.

“It’s surely impossible to argue that competition is working properly if prices are so vastly different in two parts of the UK. And if an independent retailer in the middle of Shropshire can be undercutting the supermarkets by around 6p a litre, something has to be very badly wrong.

“We continue to call on the biggest retailers to play fair with drivers and lower their prices to match what’s being charged in Northern Ireland.

“We also urge Energy Security Secretary Claire Coutinho, who is on a mission to bring greater transparency to fuel pricing following the Competition and Markets Authority’s investigation concluding drivers were overcharged to the tune of £900m in 2022, to ask the supermarkets why they won’t charge similar prices to the averages seen across Northern Ireland.”