Diesel’s undercutting of petrol may be short-lived if recent trends continue.

Plummeting prices in July sent diesel below petrol for the first time in 14 years, and by mid-August the price differential had stabilised at around 3ppl, but a flurry of petrol price cuts in the week before Forecourt Trader went to press could bring the two fuels close to parity.

The supermarkets cut 2ppl off petrol on August 21, with no cut in diesel, and Morrisons, Tesco and Sainsbury’s cut 2ppl from petrol with just 1ppl off diesel on August 27.