Diesel prices have hit a new high amid claims retailers hiked profits following the 5p per litre fuel duty cut.
Figures from the Department for Business, Energy and Industrial Strategy show the average price of a litre of diesel at UK forecourts was 179.7p on Monday.
That was up from 178.4p a week earlier.
The average price of petrol on Monday was 165.1p per litre.
That was narrowly below the record of 165.4p set on March 21, based on the Government’s figures.
Separate fuel price statistics by data firm Experian Catalist using a different methodology show average prices on Monday were 180.3p per litre for diesel and 166.8p per litre for petrol.
Chancellor Rishi Sunak implemented a 5p per litre cut in fuel duty on March 23.
The RAC said retailers are taking an average profit of 2p per litre more than before the policy was introduced to help cash-strapped motorists.
The firm’s analysis showed the average margin for a litre of petrol and diesel is currently 11p and 8p respectively.
In the month up to the duty cut it was 9p for petrol and 6p for diesel.