Supermarket sales slowed in October 2018 compared to the same time last year, with premium grocers Waitrose (-1.3%) and Marks & Spencer (-1.2%) recording a marked decline in sales, according to Nielsen data.

The report revealed that overall growth in the four weeks to 4 November was 1.5%, a slow-down in spending from 1.9% during the previous four week period, and less than half the 3.1% growth seen in the same period last year.

The data showed that of the big four supermarkets, Asda is the fastest growing (+2.5%), followed by Morrison’s (+1.2%). Tesco’s growth (+0.3%) remained ahead of Sainsbury’s (-0.6%), while discounters Aldi (+12.2%) and Lidl (+6.5%) remained ahead of the pack.

However, in-store Christmas promotions have made an impact, especially on alcohol, with sales of beers, wines and spirits rising 4.9%.

Nielsen’s UK head of retailer insight, Mike Watkins, said: “Both in-store promotions and media campaigns are more crucial than ever for the supermarkets this Christmas, to entice shoppers into their stores and ramp up consumer spending.

“With weaker than expected growth in October, the industry is under pressure to get shoppers into the habit of spending more over the next six weeks by showcasing what’s new and different in store. We expect to see some inspiring and distinctive campaigns designed to drive sales as retailers will be focused on pulling consumers in over the festive period.”