Market researcher Kantar said sales rose 10.6% year-on-year in the four weeks to Oct. 4 as shoppers moved a greater proportion of their eating and drinking back into the home.

"This is likely a response to rising COVID-19 infection rates, greater restrictions on opening hours in the hospitality sector, and the end of the government's 'Eat Out to Help Out' scheme," said Fraser McKevitt, head of retail and consumer insight at Kantar.

He noted that alcohol sales alone were worth 261 million pounds more to the grocers this month than the same month last year, with pubs, bars and restaurants now subject to a 10pm curfew.

But he said there was only limited evidence of consumers stockpiling goods at a national level.

The seven days to Sept. 27 were the busiest since March, with 107 million trips to supermarkets recorded, but that number was nowhere near the 175 million seen just prior to the first national lockdown.

That said, sales of toilet rolls and flour rose by 64% and 73% during the week, showing that consumers were wary of potential new restrictions.

Last month, market leader Tesco and No. 4 player Morrisons both reintroduced purchase limits on some products.

Morrisons was the best performer of the country's so called "big four" supermarkets, with sales up 11.5% over the 12 weeks to Oct. 4.

Sales rose 9.2% at Tesco and were up 6.8% at Sainsbury's and 5.4% at Asda.

Sales at online grocer Ocado, which started delivering Marks & Spencer products on Sept. 1, were up 41.9%.

(Reporting by James Davey; editing by Sarah Young and Mark Potter)

By James Davey