Waitrose, Aldi and Lidl were the only supermarket groups to enjoy sales growth for the 12 weeks ending 26 April, according to the latest figures from Kantar Worldpanel.

Sales at Aldi and Lidl grew by 15.1% and 10.1% respectively over the 12-week period, taking their market share to a record high of 5.4% and 3.8%.

In a sign of the continuing polarisation of the market, Waitrose’s sales grew by 1.5%, while all of the big four suffered a dip in sales. Sales at Morrisons declined by 1.1% on a year ago, while at Tesco they fell back by 1.0%, taking market share to 28.4% – a decline of 0.4% compared to a year ago.

Overall supermarket sales slow to 0.2% growth compared to last year, due to a record low in grocery price inflation.

Fraser McKevitt, head of retail and consumer insight at Kantar Worldpanel, said: “Growth in the market has declined thanks to a record low for grocery price deflation: a typical basket of everyday items is now 2.1% cheaper than it was in 2014.

“Lower costs are the result of both falling commodity prices and the ongoing supermarket price war, with all major retailers offering cheaper like-for-like goods.”