Asda had to back down on claims it made about its fuel price cuts, and reissue a press release, after it was challenged by Forecourt Trader.

In the original press release the supermarket giant claimed that from January 14 it would be offering its lowest price on diesel for 18 months, at 133.7ppl. However, Forecourt Trader pointed out that just over two months earlier, on October 30, 2013, it announced it was capping diesel at the same 133.7ppl.

An Asda spokesperson admitted: "Diesel held at around 133.7ppl in October for a few days, which was missed when we ran the data."

However she defended another claim that Asda had cut up to 2ppl off its fuel prices, even though the unleaded price of 126.7ppl was identical to the last time it announced a cut, on December 18, and diesel was only 1ppl lower at 133.7ppl. She said: "Fuel prices are constantly fluctuating on both unleaded and diesel, so it has increased since the last drop."

Andy Peake, Asda’s petrol trading director, said: "Our commitment to customers is to always be the last retailer to raise petrol prices and the first to drop them."

Asda later reissued the press release correcting the claim by saying it had reduced diesel to its lowest price for three months.