Like-for-like sales, excluding petrol, at Asda rose 6.4% in the three months to 31 March, according to the retailer's US parent company Wal-Mart.

Total sales increased in the 'high single digits', Wal-Mart said, driven by an early Easter and the extra leap day.

Mike Duke, international vice chairman of Wal-Mart, said: "Asda has continued to win in the UK - delivering a strong first quarter, with thirty basis points of market share growth, despite a challenging economic environment.”

"Although we expect the UK to remain a challenging economy and retail market over the rest of the year, we believe that our strong pricing agenda, backed by a cost reduction programme leaves us well positioned to continue to make market share there," he added.