Supermarkets Asda, Morrisons and Sainsbury’s will lower petrol prices, in a move prompted by falling oil prices.

Asda will cut the price of unleaded petrol and diesel by 3p a litre and Morrisons will cut both by 4p a litre.

Sainsbury’s will slash petrol prices by 5p a litre, but only when customers spend£50 or more.

The decision comes as oil prices have begun to fall, despite an increase earlier this month. The cuts will relieve some of the pressure on cash-strapped consumers hit by the downturn.

Asda introduces the price cuts today. Unleaded petrol is 113.9p a litre and diesel is 128.9p a litre at the retailer.

Asda trading director David Miles said: “We are seeing a more stable reduction in oil prices, allowing us to pass on the savings to customers.

“We urge other retailers to follow our lead at a time when customers need as much help as possible.”

Price changes at Morrisons will come into effect on Monday, “ensuring customers reap the benefit by passing on the saving quickly, for cheaper prices at the pump”.

The AA has called on other fuel retailers to follow suit and cut prices, after wholesale gasoline prices dropped 6 per cent since mid-July.

AA president Edmund King said: “The AA expects fuel suppliers to pass on – not pocket – the saving for the good of UK families, hauliers and the economy.

“Should fuel suppliers and retailers appear to be dragging their feet, we will seek to expose this.”