Asda, Tesco and Morrisons are reducing the price of petrol and diesel by “up to 2p per litre” from Tuesday.
Motorists will pay no more than 114.7p per litre for unleaded petrol and 116.7p for diesel at Asda’s 301 filling stations.
It was the first of the retailers to announce a price cut.
The company’s head of petrol trading, Dave Tyrer, said: “Asda is once again leading the way in reducing the price at the pumps to help the millions of motorists across the UK.
“Our new national price cap of 114.7ppl on unleaded and 116.7ppl on diesel will be welcomed by the millions of drivers who have seen fuel prices climb over the last 12 months.”
Morrisons’ services director, Roger Fogg, said: “We will always aim to drop prices as soon as we can and always keep them far below the UK average.”
A Tesco spokeswoman said: “We know that low fuel prices are important to our customers so, to provide a little extra help, we’re cutting the cost of petrol and diesel by up to 2ppl at all of our 500 filling stations.”
The cost of petrol heading to forecourts has fallen by an average 1.7p per litre in the past four weeks, according to the AA.
Last week, wholesale petrol averaged 33.8p, compared with 35.5p in mid-February.
Average diesel wholesale prices have hit a plateau of about 35.5p over the past month.
Latest Government figures show the average price of petrol in the UK is 120p, while diesel is 122.9p.
Prices in recent weeks have been higher than at any point since December 2014, partly driven by the lower value of the pound against the dollar following the Brexit vote.
RAC fuel spokesman Simon Williams said: “This is the perfect spring gift for motorists to go with longer days and warmer weather. No doubt other retailers will follow suit and we will see prices on every forecourt come down.
“While this cut may come as a surprise to drivers, as prices at the pump have been going the wrong way for months, it has been on the cards for a couple of weeks. We’re very relieved retailers have acted without any need for outside encouragement.”