Asda has turned up the heat in the latest petrol price war by cutting its prices for the third time in two weeks.
Asda said lower crude prices were behind the price drop
The group said it would be dropping prices by 2 pence to 91.9p a litre for unleaded petrol and 93.9p for diesel.
Rivals Sainsbury's and Tesco vowed to follow suit, although neither could put an exact figure on the reductions.
Until recently, prices at the petrol pump had been edging toward £1 a litre as crude oil prices hit new records above $77 a barrel.
Earlier in August the average price of unleaded was 98.43p a litre and diesel even higher at 99.62p.
Sainsbury's - which sparked the last round of price cuts five days ago - has promised to implement another price drop.
"We're currently the cheapest supermarket for fuel and going forward we will match, if not beat, our competitors on price," the group said.
The country's big three supermarkets said reductions in the wholesale price of crude oil were behind the lower petrol prices.
In Thursday morning trading, the price of benchmark US light sweet crude stood at $71.59 a barrel, down 17 cents from a day earlier, while UK Brent crude had fallen 12 cents to $71.90
"We guarantee that we will be quick to pass on cost savings to our customers and we're delivering again on this commitment by offering the lowest pump prices in the UK," said Asda director Andy Brem.