Big Four supermarkets sales sink, Nielsen shows

Along with the decline in sales values, which are being dragged down by the industry's price war, volumes also fell during the four weeks to 7 November, according to the data from Nielsen.

This compares with data simultaneously released by Kantar Worldpanel on Tuesday that showed sales up by 0.5% in a longer eight-week period.

"Heavy price-cutting to combat the discounters, coupled with deflation, is great news for consumers but increasingly problematic for the supermarkets, who are seeing less money going through the tills,” said Nielsen’s UK head of retailer and business insight, Mike Watkins.

“The rise of the discounters seems to have hit Tesco, Asda and Morrisons the hardest. Their combined market share over the last year is down 2.1%, the exact figure the discounters’ has risen.

As also shown by Kantar, Sainsbury’s was the only top-four supermarket to see an increase in year-on-year sales over the last 12-week period, with its sales rising 0.4%.

Tesco and Morrisons both saw a decrease of 1.8%, while Asda delivered an embarassing 4.7% drop.

Marks & Spencer's sales rose 3.9%, while German discounters Aldi grew 27.5% and Lidl 21.7%.