J Sainsbury has disputed a report published in The Times yesterday that said that some customers were deserting it for leading competitors for the first time in this recession.

The Times reported that, according to confidential industry “switching” data covering the 12 weeks to November 1, the supermarket group had lost business to Tesco, Waitrose and Aldi, the German discount retailer.

Of this, about £4 million of spending went to Waitrose, a further £2 million to Tesco — whose chief executive, Sir Terry Leahy, has recently claimed to be taking market share from rivals — and about £2.5 million to Aldi.

Sainsbury’s, whose shares initially fell by about 1.4 per cent on the report before closing up 0.2 per cent, claimed that it was unfair to highlight the fact that it had been losing customers to Tesco, Waitrose and Aldi. It insisted that it gained share during the period — mainly from the merged Co-op-Somerfield and from Asda and Netto.

Sainsbury’s said that “till roll” data for the same period published by TNS Worldpanel, the industry analysts, showed that it grew market share — from 15.7 per cent a year ago to 15.9 per cent in the 12-week period.

TNS Worldpanel, which also produces the switching data, said that that growth was based on Sainsbury’s acquiring 220,000 extra shoppers between these periods and its “spend per shopper” growth outstripping that of its leading competitors.

Edward Garner, TNS Worldpanel spokesman, said: “The switching analysis quoted can be run in many different ways, which normally remain confidential to our clients. In particular, the shifts between retailers are subject to short-term ebbs and flows which have no strategic relevance.”

However, grocery industry insiders insisted last night that the switching data was strategically important, expressing surprise at the fierce response from Sainsbury’s, which is thought to have been driven by Gwyn Burr, the supermarket’s customer director.

Dominic Burch, spokesman for Asda, which was shown in the switching data as losing custom to Sainsbury’s, said: “The TNS switching data is extremely useful as it enables us to identify where we need to focus more of our efforts.”

A spokesman for another leading supermarket said: “Sainsbury’s can’t pick and choose which data sets are relevant depending on what the figures say about their performance.”

Times Recommends

• Minister in talks with Saudis to protect creditors
• Premier Inn hits back in £29-a-room row
• Bankers hit back at 'populist' bonus supertax