The discounters Aldi and Lidl have continued their astonishing sales growth over the summer months, while Sainsbury's was the only grocer among the big four supermarkets to grow its market share.
Aldi grew sales by an eye-watering 31.9 per cent and Lidl by 14.9 per cent over the 12 weeks to 18 August to give them a 3.7 per cent and 3.1 per cent share of the grocery market, respectively, according to Kantar Worldpanel.
Both chains have been boosted by opening new stores and attracting additional shoppers.
Sainsbury's grew its market share from 16.4 per cent to 16.5 per cent, following sales growth of 4.9 per cent.
All its big three rivals saw market share decline, though sales rose.