TNS data showing rapid market share growth by hard discounters contributed to a fall in the share prices of quoted grocers. Meanwhile, general stores slipped still further as trading difficulties – real and imagined – undermined sentiment.

Sainsbury’s shares hit a two-year low on Tuesday, when the TNS figures showed its growth lagged behind the market average. Pali International was unimpressed by Nielsen numbers, which incorporated Marks & Spencer for the first time. The broker noted: “Over the past 12 weeks, which is basically M&S’s first quarter, M&S food sales are flat, which implies a big like-for-like decline.”

Land of Leather’s emergency fundraising and continued uncertainty about the future of ScS stoked the febrile mood about retail in the City. Not even the appointment of Wal-Mart man David Wild as chief executive of Halfords, which has shown few signs of being dented by the downturn, could prevent the motor accessories retailer’s share price going south along with the rest of the sector.

Such was the hothouse atmosphere that department store group Debenhams brought forward a trading update to calm wild speculation about its future.

Debenhams posted 1 per cent like-for-like growth for the 10 weeks since its interims. Like-for-likes were down 0.6 per cent over 42 weeks, but gross transaction value rose 1.3 per cent and the retailer made reassuring noises about debt.

Numis, which had a hold recommendation, put the stock under review “in anticipation of a material recovery in the share price” and said: “Reports of Debenhams’ demise seem premature.” Advising sell, Citi said Debenhams’ shares should benefit from the update but, with the downturn likely to be at its worst next year, “market share gains alone may not be sufficient to prevent earnings attrition”.

Sports group JJB bucked the downward trend of retail shares and was the week’s biggest riser, partly on the back of vague speculation that a management buy-out might be on the cards. There was also talk that the retailer might be a beneficiary of the Olympics, which start in August.

AIM-listed jeweller Theo Fennell celebrated a 16 per cent surge in full-year profit before tax and exceptionals to£1.9 million on sales ahead 10.6 per cent to£28 million. In the short term, said house broker Seymour Pierce, profits will be hit by one-off costs, but this should be “a year of transition” for the grocer.

Next week will bring results and updates from retailers including Asos, Carpetright and HMV.