Asda has shot back to the top of the rankings after emerging as the second-most expensive retailer for ethical products last week. But it was no easy victory, as Sainsbury's basket cost just 7p more.

Asda made a whopping nine price changes. The most dramatic hike was on the Jacob's Creek Shiraz Rosé, which rose £2.78 after a four-week promotion ended, while its biggest reduction was on the healthy-eating chicken curry with rice, which was down £1 thanks to a new round-pound deal.

Sainsbury's remained in second place, missing the top spot by a whisker. It made no hikes and was the only retailer to offer the Quorn for under £1, thanks to an ongoing promotion.

Last week's cheapest retailer Tesco slid back down the rankings with a £65.13 basket that cost 23p more than Sainsbury's. It undercut its rivals by at least 40p on the organic eggs thanks to an offer.

Morrisons slid a place to fourth and made no reductions. It added 10p to the loose red pepper, 2p to the Robinsons Whole Orange and 2p to the unsmoked back bacon.

Waitrose remained in its usual fifth place with a basket that cost over £10 more than Asda's, Tesco's and Sainsbury's. It made two hikes and one reduction, knocking 20p/kg off the bananas.