Popular train station sandwich chain Upper Crust is warning of job losses of up to 5,000 as the coronavirus continues to decimate passenger numbers.
Owner SSP, who also run Caffe Ritazza and Millie's cookies, say it is in the middle of a shake-up to save the business, which operates across railway stations and airports.
It recently warned of massive operating losses of up to £250 million for the second half of its financial year.
It has 570 sites across 130 airport and railway stations in the UK and Ireland, as well as operations in 35 countries worldwide, but only fifth of its UK sites will reopen by the autumn as travel is set to remain at very low levels.
A restructuring plan is now underway to "simplify and reshape" the business in the face of the pandemic, which it said could lead to more than half of its 9,000-strong peak season workforce being axed.
The group said head office and UK staff would be affected by the cuts.
Chief executive Simon Smith said: "In the UK the pace of the recovery continues to be slow.
"In response to this, we are now taking further action to protect the business and create the right base from which to rebuild our operations.
"Regrettably, we are starting a collective consultation which will affect our UK colleagues.
"These are extremely difficult decisions, and our main priority will be to conduct the process carefully and fairly."
As well as its own food brands the company runs travel sites for chains such as Burger King, M&S Simply Food and Starbucks.
The firm has so far not launched any "material" restructuring in its other global operations, as it believes there will be a faster bounce back outside the UK.
SSP has seen sales almost entirely wiped out in April and May, down around 95% and, despite a slight recovery in June, revenues were still around 90% lower last month.
The firm said despite small signs of a recovery in the travel sector, rail passenger numbers still remain around 85% lower than a year earlier and the air sector has stayed largely closed until recently.
It believes that short-haul air travel may see a limited pick-up in July thanks to so-called air bridges between countries over the summer holiday season, but it does not expect things to really pick up.
Mr Smith said: "The objective of the action that we are proposing today is to ensure that we manage through this pandemic, rebuild our business as demand recovers and, in time, deliver long term sustainable growth for the benefit of all our stakeholders."
He added the group will keep open the possibility of opening more sites if it sees sales improve over the summer.
Mick Lynch, assistant general secretary at rail union RMT is calling for the Government to intervene.
He said: "The news that Upper Crust, major caterers on Britain's railway stations, have announced savage job cuts shows that support services across the rail industry are facing a real crisis in the months ahead which will hammer both the workforce and those who rely on their facilities if the Government doesn't intervene as the lockdown eases.
"Our railway stations are in danger of ending up as ghost towns as we emerge from the pandemic.
"Every member of the rail workforce from caterers to cleaners and those who operate trains and track is important to our future success and RMT will be demanding of the Government that no one is left behind."