Hays Travel has begun consultation on as many as 878 job losses as the tourism sector continues to battle the fallout from the Covid-19 pandemic.
The company, which took on 2,000 former Thomas Cook employees when it went bust in October last year, currently had around 4,500 employees.
However, cuts are now likely following a government decision to reimpose quarantine procedures for travellers returning from Spain.
Owners John and Irene Hays said the restrictions meant hundreds of thousands of holidays had been cancelled.
They were “devastated” staff would lose jobs “through no fault of their own,” the couple said.
In a joint statement, the Hays said they had “made every possible effort” to protect the jobs of all the staff, “including those who were employed when Hays Travel took on the Thomas Cook shops last October”.
The Sunderland-based company said it was now consulting with 344 staff training as travel consultants and the 534 who work in the foreign exchange division.
The firm said its experienced travel sales staff, apprentices and other head office staff were not affected by the cuts.
Hays Travel said it had a two-year turnaround plan in place, and that although 2020 “looked really bad,” bookings for 2021 were already up on the same period in 2019.