Supermarkets are to cut petrol prices following falls in the wholesale cost of fuel.
Both Asda and Tesco are cutting up to 4p a litre off the price of petrol from today.
The news comes as fuel protesters prepare a motorway go-slow which they claim still has massive support.
From the morning the nationwide maximum price at all of Asda's 158 petrol stations will be 89.9p/litre for unleaded. Prices will also come down for diesel drivers with a new maximum price of 92.9p/litre at all stations.
The company has pledged to publish its maximum prices on its website (www.asda.com) and is challenging other forecourt operators to do the same.
Asda's general merchandise director Tony Page said: "Drivers have been ripped-off in the past ten days as drivers rushed to fill up.
"Quite frankly we've been shocked at some of the prices we've seen elsewhere - here at Asda we think customers deserve better than to be treated like that."
A Treasury spokesman said: "We welcome the lead being taken to reduce retail prices in Britain in response to the easing of wholesale prices, and we hope other companies will follow suit.
"However, it is because we understand the problems faced by motorists, hauliers and farmers at this time that we will never be complacent and we are stepping up our efforts to lead concerted global action to bring down world oil prices and stabilise the market for the long term."
He added: "The Chancellor is writing to finance ministers from all the countries attending next week's international meetings setting out his proposals for a global action plan and calling on them to respond next week.
"And we have made clear that we expect oil companies to take early action to reduce their prices in response to any easing of world pressures, and that we want oil producers to increase their investment in refining capacity."
Meanwhile, despite the failure of refinery blockades across the UK on Wednesday, fuel protesters in Wales claim public support is rising.
Alan Greene, of the Welsh Hauliers and Public Less Tax on Fuel Campaign, says the strategy to avoid blockading refineries in Wales has paid off. He will be leading a convoy of lorries, coaches and taxis on a 20mph go-slow east along the M4 this morning.