Drivers are being charged 20p per litre more for diesel than petrol despite there being little difference in the fuels' wholesale prices.
A litre of diesel is being sold at an average of around 168p while petrol is just 148p. However, the RAC has found that diesel's wholesale price - the amount that retailers pay for fuel - was just 6p per litre more than petrol last week.
The RAC is now urging retailers to cut diesel pump prices to "fairer levels" which reflect costs instead of "subsidising" cheaper petrol by taking a margin of 20p on every litre of diesel they sell.
