The UK's two biggest supermarket chains, Asda and Tesco, are battling it out to stock the cheapest goods, trade magazine The Grocer has said.
Tesco is the UK's biggest supermarket, with a 29% share of the market
Tesco has been named the UK's cheapest supermarket, edging out rival Asda last week for the first time in seven years.
An average shop at Tesco cost £167.84, 0.4% less than at Asda, according to the Grocer 100, which compares prices of goods bought at major supermarkets.
However, it did say that on average, Asda was the cheapest place to shop.
Between 6 July and 14 December, Wal-Mart owned Asda consistently topped the price table, with the 100 goods costing an average of £167 compared to Tesco's £169.74 bill.
However, since July Tesco has been closing the gap on Asda, with an average 2.7% cut in its prices.
The bill for the same items at Sainsbury's was £175.30.
But with shop sales suffering earlier in the year as consumers fretted about debt while bad weather kept shoppers off the High Street, many retailers have been slashing prices to encourage spending.
Sainsbury, the UK's third-largest supermarket, remained more expensive than its rivals, even though its prices have fallen since July.
The Grocer does not reveal what items are in its weekly top 100 price checks - but the list does cover branded and own-brand products, ranging from fish and poultry to fruit and vegetables.
However, Asda was nonplussed by the news saying it "did not play" the weekly survey game, instead preferring to concentrate on keeping prices low all of the time.