Tesco, Sainsbury and Asda have all shaved 2p off their petrol prices in an effort to out bid one another at the pump.
This latest battle was initiated by Asda on Wednesday and was closely followed by its rivals.
Drivers steering their way to Asda will hand over a maximum of 133.7p a litre for petrol, although diesel has remained unchanged.
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Paul Watters, the AA's Head of Public Affairs, said: "Last week, our fuel-price report pointed to a 4p drop in petrol wholesale prices working its way through the system.
"UK average petrol pump prices reached a late summer high of around 140p a litre in mid September and sat there for more than a fortnight. More than a month on, the average petrol price yesterday was down to only 138.70p a litre."
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