The Co-op achieved its best sales growth in almost seven years as grocers generally benefited from the summer heatwave.

The Co-op’s sales advanced 7.8% in the 12 weeks to August 12, the latest Kantar Worldpanel data shows.

It drew 263,000 new customers in the period, when it won an average 22 customer visits and added 0.3 percentage points of share to speak for 6.6% of the market.

Co-op sign

The Co-op attracted 263,000 new customers

Kantar Worldpanel head of retail and consumer insight Fraser McKevitt said: “The last time Co-op saw sales growth of 7.8% it was still benefiting from the acquisition of Somerfield, so its performance is particularly notable.”

The wider grocery market notched up sales growth of 3.5% and the growth of branded products outstripped own-label for the first time since May 2015.

McKevitt said: “Consumers’ willingness to spend that little bit extra to fully enjoy the summer sunshine has helped push brands ahead of their own-label counterparts.

“At Tesco and Sainsbury’s, branded growth has outstripped own-label for a while and, as the two biggest retailers in the grocery market, this has contributed to the market shift.

“More expensive premium own-label lines across the market are still growing strongly though – up 6.3%.”

Among the big four, Morrisons led the way with sales growth of 2.7% to hold market share steady at 10.4%.

Asda’s sales growth continued, up 2.6%, while its market share slipped 0.1 points to 15.2%.

Tesco’s sales rose 1.8% and its market share fell 0.5 points to 27.4%. Sainsbury’s sales advanced 1.2% and its market share was down 0.4 points to 15.5%.

Aldi and Lidl generated sales growth of 12.6% and 8.6% respectively, winning them market shares of 7.6% and 5.5%.

Separate Nielsen data showed that Marks & Spencer’s food sales rose 1.2% in the 12 weeks to August 11. Its market share was unchanged at 3.3%.