TUI is set to shut 166 high street stores across the UK and Ireland.
The tour operator said it hoped to keep on 630 workers in a mix of sales and home-working roles and in remaining stores.
About 350 retail stores will remain across the UK and Ireland following the closures.
TUI said it will not release the list of stores at risk during the consultation period.
Andrew Flintham, Managing Director of TUI UK and Ireland said: “We want to be in the best position to provide excellent customer service, whether it’s in a High Street store, over the telephone or online, and will continue to put the customer at the heart of what we do.
“It is therefore imperative that we make these difficult cost decisions, look after our colleagues during such unprecedented uncertainty and also offer a modern customer service.
“Customer behaviours have already changed in recent years, with 70% of all TUI UK bookings taking place online.
“We believe Covid-19 has only accelerated this change in purchasing habits, with people looking to buy online or wishing to speak with travel experts from the comfort of their own home.
“We have world-class travel advisers at TUI, so we hope many of them will become homeworkers and continue to offer the personalised service we know our customers value.”
Julia Lo Bue-Said, CEO at Advantage Travel Partnership said: “This is a sad day for the travel industry and for the British high street with the closure of so many TUI stores. Whilst such draconian quarantine measures are still in place, we will be nowhere nearer to getting the industry back on its feet. Without specific sector support and consultation from government, many businesses will not see it through the next few months.”