According to the latest figures released by market tracking agency TNS, Tesco lost share in the UK grocery sector with rivals Asda and Sainsbury's both posting higher sales gains for the three months to 25 March.

Asda was the fastest growing food retailer, with year-on-year growth of 9%, followed by Sainsbury's with sales growth of 8%. Tesco, the UK's largest retailer, posted sales growth of 7%.

Ed Garner, director of research at TNS, said that Sainsbury's and Asda were benefiting from turnaround plans brought in by their relatively new management teams.

"Both Asda and Sainsbury post strong year-on-year growths of 9% and 8% respectively. Surprisingly, these growth rates are now ahead of that for Tesco although at 7% it is still comfortably ahead of the market," Garner said.