Britain’s “Big four” supermarket chains have surrendered more ground to their discount rivals, new figures revealed today.

Tesco’s share of the market fell to 28.6% in the 12 weeks to March 30, from 29.7% a year earlier, Asda’s to 17.4% from 17.6%, Sainsbury’s to 16.5% from 16.9% and Morrisons’ to 11.1% from 11.6%.

In contrast, the data from Kantar Worldpanel showed Aldi’s share rising to 4.6% from 3.4% while Lidl’s grew to 3.4% from 2.9% .

Kantar added that Waitrose had held on to its record 5% share, while the Co-op appeared to have stemmed recent losses by stabilising at 6.1%.

Overall grocery sales grew by just 0.6% in the 12 weeks, and Kantar said that, even adjusted for this year’s later Easter, the figure was still low by historical standards at 1.5%.

Kantar Worldpanel director Edward Garner said: “All of the ‘big four’ supermarkets have faced declining sales over the past 12 weeks, which has been accentuated by the late falling of Easter.

“Nevertheless, they have also seen worrying share declines, with the most resilient performance coming from Asda this period.”