Figures from data firm Experian Catalist show the average price of a litre of the fuel at UK forecourts was a record 182.7p on Saturday and 182.6p on Sunday.

That brought the cost of a full tank for a 55-litre diesel car to nearly £100.50.

RAC fuel spokesperson Simon Williams said: “With crude oil prices consistently above 115 US dollars a barrel last week, worse is sadly yet to come just in time for the Jubilee bank holiday, particularly as petrol is now more expensive than diesel on the wholesale market.

“Due to the rapid rise in the cost of wholesale unleaded, retailers are now taking smaller margins on petrol but larger ones on diesel.

“If the wholesale price of petrol stays above diesel, we ought to see the current 10p-a-litre gap in average petrol and diesel forecourt prices narrow.

“If this doesn’t happen diesel drivers will be getting a raw deal, and with prices at these historic highs, every penny matters to drivers.”

“However, a diesel car’s 15%-20% better fuel consumption compared to a petrol equivalent out on the open road means less CO2 emissions, and would it make it more attractive were it not for the current higher cost of refuelling.”