Kantar numbers show Sainsbury's is winning the supermarket wars, but Tesco is slowing sales decline

Sainsbury's was the only big supermarket to grow sales

Sainsbury's is leading the fight back against discount chains Aldi and Lidl (Getty Images)

Sainsbury's is winning the supermarket wars, according to the latest data from Kantar World Panel, a market research company.

Sainsbury's is leading the fight back against discount chains Aldi and Lidl. It was the only one of the big four - Tesco, Sainsbury's, Morrisons and Asda - to grow sales in the 12 weeks ending February 28. That gives it the longest run of sales growth for any of the main retailers since March 2013.

Its 0.5% sales rise matched that of the overall market, though Kantar said this was still being held back by the ongoing price war and food deflation. Food prices are down 1.6 per cent across the board.

The data shows that Tesco is making some progress with a turnaround plan that has slowed its declinning sales.

Tesco sales dropped 0.8 per cent in the 12 weeks ending February 28 versus a 1.6 per cent decline the previous month.

Kantar's head of retail and consumer insight Fraser McKevitt said: “A renewed focus on price promotions has helped stem the flow of shoppers leaving the retailer despite the closure of around 50 stores in the last year.”

Under chief executive Dave Lewis, Tesco is attempting to come back from a string of profit warnings and an accounting scandal. It is also trying to stave off the threat of discounters Aldi and Lidl, which are increasingly encroaching on traditional grocers' territory.

The supermarket, Britain's biggest, surprised at Christmas with a better-than-expected 1.3 per cent rise in sales.

Grocers have dropped their prices to compete with Aldi and Lidl, where sales were up 15.1 per cent and 18.9 per cent, respectively.

There was however an increase in spending on chocolate, flowers and sparkling wine as shoppers stocked up for Valentine's Day and in preparation for Easter.

The Co-operative also made some progress. Sales jumped 1.9 per cent and the grocer increased its market share to 6 per cent thanks to “an increase in shopper frequency”.