Morrisons booted Asda out of top spot this week, largely thanks to its bargain salmon fillets, which undercut all of its rivals' offerings by at least 64p/300g.

The retailer offered 20 of the cheapest or joint-cheapest items. Promotions began on the Aunt Bessie's Baked Yorkshire Puddings, which were down 20p, white bread rolls, down 27p and McCain Home Fries, down 58p. It also added 10p to the fresh penne pasta.

Sainsbury's beat Tesco to second by a whisker. It made three reductions, the most dramatic being a 50p cut on the large pineapple, as a new round pound deal began.

Tesco remained in third position with a £49.96 basket. It changed few prices week-on-week, upping the houmous by 14p and the Mr Kipling Deep Filled Bramley Apple Pies by a penny.

Asda slumped three places to fourth, but its basket cost just 2p more than Tesco's. It knocked 2p off the Stella Artois, while its large pineapple was up 67p after a round-pound deal ended.

Waitrose was the priciest retailer once again, with a basket costing £7.89 more than its nearest rival's. The retailer's salmon fillets were more than double the price of Morrisons'. It made few price changes week-on-week, but added 5p to the oranges.