Asda has proved to be the cheapest retailer yet again with a £57.78 basket in a week of vigorous pricing activity among the retailers.

The cheapest retailer undercut second-place Sainsbury's by £1.58 and boasted 12 promotions as well as 23 of the cheapest or joint-cheapest items. A 2p price cut on Kellogg’s Nutri-Grain and promotions starting on Birds Eye cod, down 54p and Birds Eye Chicken Dippers, down by £1.14, helped it net first place. There were three significant price hikes, however – mature Cheddar slices were up 60p, cauliflower 10p and celery 10p.

Sainsbury's leapfrogged from fourth to second place thanks to one significant reduction and 11 of the cheapest or joint-cheapest items. Fairy Liquid was down 33p as a promotion started. Birds Eye peas were also down 1p and Kellogg’s Optivita by 2p. Apples were up 4p, cauliflower up 21p and Dolmio sauce up 34p, however.

Tesco maintained its third-place status, with a basket costing £1.06 more than Sainsbury's. It boasted 14 of the cheapest or joint-cheapest items as well as the most pricing activity of the retailers, having made four hikes and four reductions. Birds Eye peas were down 1p, celery down 11p, organic chopped tomatoes down 16p and Flora Light down 71p as a promotion began. However, cauliflower was up 21p, Kellogg’s Nutri-Grain up 1p and pears up 33p, while a promotion ending led to a 64p hike on Birds Eye Chicken Dippers.

Four price hikes resulted in Morrisons sliding a place to become the second most expensive retailer. Its £61.50 basket cost 2% more week-on-week – the highest increase of all the retailers. Celery was up 18p, Dolmio sauce up 17p, Patak’s sauce up 2p and Nescafé up £1.14 after a promotion ended.

There were also two price cuts, on Birds Eye Chicken Dippers, down 6p, and Birds Eye cod down 25p. Fifth-placed Waitrose’s basket cost £9.65 more than Asda’s. It upped apples by 10p but Listerine Mouthwash was down 6p.