Promotions on Asda's thick pork sausages and Listerine mouthwash helped the retailer secure the top spot this week.

Asda's £44.70 basket undercut second place Morrisons by 50p and offered 21 of the cheapest or joint-cheapest items. It was the only retailer to offer the organic eggs for under £2 and made four reductions as well as four hikes.

Two new promotions helped Morrisons leapfrog two places to second. It knocked £1.50 from the battered cod fillets and 68p/kg from the broccoli. It also sliced 28p from the iceberg lettuce and made two hikes.

Tesco slipped to third with a basket that cost 78p more than Morrisons'. It made two hikes and began two promotions, knocking 38p from the fresh pasta sauce and 98p from the Stella Artois.

Sainsbury's tailed behind in fourth place, but its basket comfortably undercut Waitrose's by a £6.53 margin. It was the only retailer to offer the Old El Paso Fajita dinner kit for under £2 thanks to a new promotion. It made four hikes, the most dramatic a 20p rise on the iceberg lettuce.

There was little pricing activity at Waitrose, which remained the priciest retailer. It sliced 3p/kg from the apples and added 10p to the olive oil.