Sainsbury’s was the only one of the big four to increase its market share in the past 12 weeks, according to the latest data from Kantar Worldpanel.

The retailer increased its share from 16.9% to 17% in the 12 weeks to 17 February, with market-beating sales growth of 4.6%.

In contrast, Tesco’s share dropped from 30.1% to 29.7%, while Asda’s fell from 17.8% to 17.7%. Morrisons, meanwhile, was the only one of the big four to post a decline in sales (-1.3%), with its market share also falling – from 12.4% to 11.8%.

Beyond the big four, Waitrose, Aldi and Lidl all continued their strong run with sales growth of 8.9%, 30.1% and 11% respectively. The Co-op also continued its recent resurgence, chalking up sales growth of 0.3%.

Explaining the Tesco decline, Kantar Worldpanel director Ed Garner said: “Tesco undertook heavy promotions this time last year, where consumers received a £5 voucher when they spent £40, and not repeating this offer will have adversely affected its share.”

Kantar Worldpanel also revealed that frozen burger sales fell 43% in the four weeks to 17 February in the wake of the horsemeat scandal. Frozen ready meal sales fell 13% in the four-week period.