Tesco has failed to hold on to the crown of cheapest supermarket, after it broke Asda's five-week-long spell at the top last week. Asda's total of £49.04 was the cheapest of the six supermarkets in our survey this week. Tesco was second at £51.36, or £2.32 more than Asda.

Asda posted an impressive ­performance in this week's survey, as it set or matched the overall lowest price for all but one item: ­Parozone bleach.

That said, the race at the top was closer than indicated by the 4.7% gap between Asda and Tesco. Comparing their pricing head to head, the rivals were dead even on 28 of the 33 items in this week's shopping basket. Asda was cheaper on the other five items, but much of the difference was attributable to just one item: Jacob's Creek Chardonnay wine, for which Asda's promotional price of £4.48 was £1.49 less than Tesco's.

Asda posted two price changes in this week's shopping basket. It reduced the price of Nestlé Shreddies by 30p to £2.00 and increased the price of own label mushy peas by 3p, to £0.18.

Tesco put up the price of McCain hash browns by 20p to £1.19. Sainsbury's closed at third, at £51.56, 20p more than Tesco and 5.1% more expensive than Asda.

Morrisons returned to fourth place this week with a basket price of £52.09, after it had pulled back to third last week. Morrisons' total was 6.2% more expensive than Asda's benchmark for the week.

Waitrose clawed its way back into fifth place this week. Its price total for this week's shopping list was £58.37, or £9.33 more than Asda's basket.

Somerfield was sixth and last with a total price of £59.37. Somerfield did manage to best Asda on the price of Parozone bleach, but otherwise was far behind. Its total price was a whopping 21% more than Asda's first place mark. Somerfield dropped the price of its own label mixed vegetables by 2p to £0.92. It also increased the price of own label Brussels pâté by 2p to £0.67 and put up the price of loose apples by 3p to £1.32.