Sainsbury's said petrol prices at the company's 279 forecourts will dip by 4p a litre, with diesel being reduced by 3p a litre, from Wednesday.
Hard-pressed motorists have received some respite after supermarkets Sainsbury's and Asda both announced fuel-price cuts.
Then Asda said it would also be cutting its petrol by up to 3p a litre and its diesel by up to 2p a litre from Wednesday.
Asda said that from Wednesday drivers would pay no more than 134.7p a litre for petrol and 141.7p a litre for diesel.
Sainsbury's head of fuel Richard Crampton said: "We know that fuel is a big part of many customers' weekly budget so we're keen to do anything we can to help."
Andy Peake, Asda's petrol trading director, said: "We always aim to be the first retailer in each part of the country to drop prices when costs are falling and the last to put them up.
"When we do drop prices, we drop them everywhere, setting a maximum national price cap for our customer, which means they all benefit from our low prices, regardless of where they live."
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