Sainsbury’s is continuing to suffer from availability problems on fresh lines after a glitch left shelves bare in some of its London based convenience stores this week.

However, a spokesman for the struggling retailer insisted the error had nothing to do with its troubled supply chain: “It was an isolated problem, affecting just a handful of stores.”

The retailer said fewer than 20 Sainsbury’s Local stores in the City and the West End were hit by the problem. Notices were posted on the shelves, apologising for the poor availability of all fresh lines.

The news is an embarrassment to chief executive Justin King who last year said he was very confident Sainsbury’s could “cope with Christmas”.