Asda remains the price leader this week, but Tesco has drawn much closer than it did last week, when it dropped to a suprising fourth place on our pricing table.
Tesco's basket came in at £40.81 this week, just 66p higher than Asda's at £40.15.
Much of this progress appears to have been achieved through everyday pricing, although our mystery shopper noted that the Tesco she visited was promoting multibuys on almost one fifth of the items in the basket.
Our shopper at the Asda superstore in Handsworth Road, Sheffield, noted an equal level of multibuys on items in the shopping basket, as well as a large number of special offers.
Morrisons was a close third this week with a basket price of £41.04. This followed Morrisons' two consecutive weeks as the second-cheapest supermarket as the company continued its quest to increase market share. Our mystery shopper came across several price point offers and multi-buys at the Morrisons store in Kidderminster, Worcestershire.
Sainsbury's drops one spot to fourth place this week with a basket price of £41.76, 1.75% higher than Morrisons. Much of the basket price gap between the two companies was driven by Sainsbury's significantly higher prices on own label Brussels pâté and Nescafé Original coffee.
Somerfield came in fifth once again. Its basket price of £45.17 was 12.5% higher than Asda in first place. This was a decline from last week when Somerfield's basket price was 12.2% higher.
Somerfield's cheapest own label toilet cleaner cost £0.74, or three times as much as the top four supermarkets.
Somerfield also charged £3.95 for own label fresh kippers, which is one third more than most of its rivals.
Waitrose's own label kippers came in at an eye-watering £5.45, which accounted for most of the gap that left it in sixth place behind Somerfield with a basket price of £48.32.