The gap between the price of diesel and petrol has reached nearly 25p per litre.
According to latest government figures, the average price of a litre of diesel is 188.9p. Petrol currently stands at 164.4p per litre - 24.5p cheaper than diesel.
Analysis by the PA news agency found this is the largest price difference in records dating back to June 2003. Since then, diesel has typically cost around 5p per litre more than petrol.