The global information and insights company predicts that British consumers are intending to leave their Christmas shopping late this year, with 60% planning on doing their main grocery shop just a week before Christmas Day.
Looking back, in the four weeks ending 5 December, sales value at till dropped 1% compared with the same period last year, while volumes fell 0.8%.
Asda suffered the largest drop among the top 10 supermarkets for the 10th consecutive quarter, with sales down 4.3% year-on-year.
Conversely, Sainsbury’s was the only Big Four supermarket to experience an increase, with year-on-year sales up 0.5%; while the German discounters fared well - Aldi grew sales by 24.4% and Lidl by 19.8%.
Mike Watkins, Nielsen’s UK head of retailer and business insight, said: "[Plans to leave shopping late this year] could provide a welcome boost for grocery retailers, particularly with an extra weekday of trading before Christmas compared to last year.
"However, it’s the discounters which could make another leap in market share -- a third of people are expecting to do their main Christmas shop at Aldi or Lidl.