PLUNGING world oil prices have prompted leading supermarkets to cut the cost of their fuel.

First, Asda announced it was knocking 2p a litre off its petrol and diesel from today.

Then Tesco said it was cutting its petrol and diesel by 2p a litre - from yesterday afternoon.

This was followed by Morrisons saying it was reducing petrol and diesel by up to 2p a litre from today. And the remaining big four supermarket Sainsbury's announced it would be cutting up to 2p a litre from its petrol and diesel, also from today.

The Asda reduction means drivers will pay no more than 117.7p a litre for petrol and 121.7p for diesel.

It is the company's seventh cut in two months and means its petrol has gone down by 9p a litre and its diesel by 8p a litre since the end of September.

RAC fuel spokesman Simon Williams said: "As Opec decided not to cut production yesterday, the Brent crude price dipped to $70.68 a barrel at the end of the day, which is the lowest it has been since June 2010.

"This means there will be more oil in circulation than there is demand. The result is excellent news for motorists this Christmas, with the cheapest forecourt prices for four years."

Mr Williams added: "But if retailers are truly going to reflect the wholesale price savings, today's cuts should be the first of several in the coming weeks."

AA spokesman Luke Bosdet said: "Asda has stood out this month as the driver of lower prices but that leaves towns without their presence often lagging behind."