Sainsbury’s is the only supermarket among the top four retailers to improve its market share in the last 12 weeks, experiencing a 4.6% growth rate year-on-year.

Research firm Kantar Worldpanel revealed the latest grocery share figures, for the 12 weeks to 17 February, revealing both Tesco and Asda saw a year-on-year (YOY) decline in market share of 0.4% and 0.1% respectively.

Morrisons was reported as the only supermarket retailer to post a sales decline, and dropped 0.6% YOY taking its current total market share to 11.8%.

The research firm said the overall results revealed the impact of the first five weeks of the horsemeat scandal, which broke in January.

Edward Garner, director at Kantar Worldpanel, said: “So far the issue has only affected the performance of individual markets rather than where consumers are choosing to shop. For the four weeks ending 17 February, frozen burger sales were down by 43% and frozen ready meals declined by 13%, clearly demonstrating a change in shopping habits.

“Tesco’s share has come under pressure during this period, with a drop from 30.1% a year ago to 29.7% now.  It might seem natural to attribute this decline to the horsemeat contamination; however, 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.”

He added that Waitrose and Aldi delivered all-time record shares during the period of 4.8% and 3.3% respectively, indicating a market polarisation and the continuation of the ‘two nations’ consumer climate.

Iceland also reported a 10.1% record growth, which Garner said confirmed the frozen food category as a whole remained robust.

Grocery inflation stood at 4.3% for the 12-week period to 17 February, which Kantar Worldpanel said remained higher than the market growth of 3.7% and reflected shoppers’ coping strategies of switching products and retailers and seeking out offers.