Asda put clear air between itself and its rivals for the fourth week running, thanks to five promotions and 24 of the cheapest or joint-cheapest items in its £44.19 trolley.

The cheapest retailer undercut second-placed Tesco by £2.21 and was the only retailer where Andrex was less than £2 and runner beans were under £1. There were two significant reductions – Cathedral City Mature Cheddar by 23p and a promotion on Young’s premium scampi resulted in a 95p cut. There were also two significant hikes – Kellogg’s Optivita up by 23p while a promotion ended on Quorn mince, which was up 48p.

Tesco leapfrogged from fourth to second place. Five promotions and 14 of the cheapest or joint-cheapest items helped the retailer pip nearest rival Morrisons to the post by 84p, with just one significant hike and two reductions. HP sauce was up 67p after a promotion ended, peach slices were cut by 7p and Flora Light was down 14p.

It was another low-key week at Morrisons, which remained in third place and provided 12 of the cheapest or joint-cheapest items. There was just one price hike – sweet potatoes up by 20p per kg; and two cuts – bananas by 9p per kg and mouthwash by 7p.

Pricing activity was high at Sainsbury's, which surrendered last week’s second place to fourth. The retailer provided three promotions and 13 of the cheapest or joint-cheapest items. It had three reductions – apples by 6p per kg, red peppers by 12p and bananas by 5p per kg. The expiry of promotions resulted in hikes on J20 apple and raspberry by 73p and sweet potato rising 69p per kg.

Waitrose maintained its usual fifth place this week, with just the Nutella and Quorn mince undercutting the competition.

There were no reductions, and the retailer significantly upped a whopping four items – chorizo by 24p, HP Sauce by 27p, red peppers by 7p per kg and Trebor Extra Strong Mints by 22p.