Greene King has warned that between 25 and 30 of its pubs are likely to stay permanently closed due to the coronavirus pandemic.
Tighter lockdown restrictions have led to the Suffolk-based pub giant keeping 79 sites closed for the time being, with around one third of these not expected to trade again.
A spokeswoman for Greene King told the BBC that the enforcement of new roles was never going to be viable for all its sites.
“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.”
It is thought that up to 800 roles could be affected by the news, although Greene King has promised to find positions for them where it can.
“We are working hard with our teams to try and find them a role in another of our pubs wherever possible.”
Greene King operates 3,100 pubs, restaurants and hotels in the UK.