Some 57% of British consumers have been severely or moderately affected by the cost of living crisis so far, and in three months that figure is expected to rise to 76%, based on data from market researcher NielsenIQ published on Wednesday.

Britons are contending with inflation that was 9.9% in August and is expected to rise further this year, driven mostly by the surge in energy prices.

Mike Watkins, NielsenIQ’s UK head of retailer and business insight, said households were shopping around for savings across different retailers, with consumers increasingly focusing on the cost of their weekly groceries to help manage budgets.

NielsenIQ's data showed that supermarket sales in the week ending Sept. 10 dipped to 2.48 billion pounds ($2.82 billion) - the lowest level since a lull in the week after Easter.

It said in the four weeks to Sept. 10, some 400 million pounds less was spent at supermarkets year-on-year as shoppers reined in spending at the start of autumn.

The market researcher said German-owned discounter Lidl remained the fastest growing grocery retailer over the 12 weeks to Sept. 10, with sales up 9.4% year-on-year, echoing data from rival Kantar published last week.

Market leader Tesco's sales were up 3.6%, while Sainsbury's was up 4.5% and Asda up 5.0%. Morrisons' sales fell 1.7%, while discounter Aldi's were up 3.7%.

NielsenIQ said online's share of the grocery market fell to 11.1%, versus 11.3% recorded last month and 12.3% a year ago. ($1 = 0.8781 pounds) (Reporting by James Davey. Editing by Jane Merriman)