Year-on-year growth at the UK’s leading supermarkets slipped by almost 1% over the last month, according to new data from market analyst Nielsen.

Latest figures from the body show that growth of UK grocery sales slipped to 5.4% over the three months to 4 October, driven down by a growth rate of just 4.5%  for the most recent four-week period.

Tesco maintained its dominant position with a market share of 28.3%, while Asda increased its own share to 15.4%, widening the gap over Sainsbury’s on 13.9%.

Morrisons showed the strongest rate of growth among the largest retailers, up by almost 10% over the last month.

“Shoppers are still trading down [and] the ‘cascade of custom’ from those retailers with a premium proposition to those that have a heritage in value for money and price continues,” said Nielsen retailer services senior manager Mike Watkins. “Family shoppers in particular are trying to save money, with 70% saying on they are looking to economize on grocery shopping, up from 63% in June.”

He added: “While it’s too early to fully assess the impact of the launch of the new Tesco Discount brands… 600,000 more people came into Tesco in the four weeks to 4 October compared to the same period last year. But with shoppers cutting back on the number of items they are putting into their baskets and buying cheaper items across all retailers, we will know in four weeks’ time if this is enough to significantly increase the spend going through the Tesco tills.”