Britain's biggest supermarket Tesco recorded its strongest sales performance in 18 months, industry data showed on Tuesday, adding to evidence new boss Dave Lewis' turnaround plan is making an impact.

Market researcher Kantar Worldpanel said Tesco’s sales in Britain rose 1.1 per cent over the 12 weeks to March 1st.

The increase helped Tesco arrest its falling market share, which was down just 0.1 percentage point to 28.7 per cent compared with last year.

Lewis has cut prices on fresh produce and branded goods, and improved customer service and product availability in an attempt to win back the shoppers that deserted Tesco in droves for cheaper rivals Aldi and Lidl.

Though Aldi and Lidl recorded sales increases of 19.3 per cent and 13.6 per cent their growth is slowing.

Kantar said Tesco’s resurgence has impacted Asda, which competes for many of the same shoppers as Tesco. Asda sales fell 2.1 percent, taking its market share down to 17.0 per cent. Sales at Sainsbury’s and Morrisons, the number three and four players, fell 0.5 per cent and 0.4 per cent respectively.

Kantar said the overall grocery market grew sales 1.1 per cent in the 12 week period. Deflation reached a new low of minus 1.6 per cent as price competition between the supermarkets continued to impact the market.

Last month’s Kantar data showed Tesco increasing its sales for the first time since January 2014.