Pub giant Greene King is to close more than 25 pubs and cut 800 jobs.
It blamed tighter coronavirus restrictions and the winding down of the furlough scheme, which had made it a “challenge” to reopen some of its sites.
It urged the government to provide more support for the struggling hospitality sector.
An industry body warned on Tuesday that half a million hospitality jobs could go by the end of the year.
A spokeswoman for Greene King said: “The continued tightening of the trading restrictions for pubs, which may last another six months, along with the changes to government support was always going to make it a challenge to reopen some of our pubs.
“Therefore, we have made the difficult decision not to reopen 79 sites, including the 11 Loch Fyne restaurants we announced last week.
“Around one-third will be closed permanently and we hope to be able to reopen the others in the future.”
She added: “We are working hard with our teams to try and find them a role in another of our pubs wherever possible.”
Suffolk-based Greene King owns roughly 2,700 pubs, restaurants and hotels in total across the UK.
The hospitality sector has been struggling with government restrictions designed to slow the spread of coronavirus, including 10pm closing time for pubs, social distancing measures, and mandatory table service for food in licensed premises.
Under the government’s furlough scheme, workers put on leave have been able to get 80% of their pay, up to a maximum of £2,500 a month.
But that scheme has been winding down and at the end of October will be replaced by the Job Support Scheme – a less generous wage support scheme.
There are fears this will trigger large scale job cuts among businesses struggling to cover their costs.