Upper Crust owner SSP Group says up to 5,000 jobs could be cut across its UK outlets and head office, as it struggles with the reduction in passenger travel.
The firm said global sales in April and May were 95% below the previous year's.
SSP expects only one fifth of its UK outlets at railway stations and airports to be open by the autumn.
The firm has seen its revenues severely hit by the impact of the pandemic on domestic and foreign travel.
It joins a growing list of companies slashing jobs as the UK economy suffers its worst contraction in 41 years.
SSP employs around 30,000 staff worldwide across 2,500 outlets. Last month, it said it had suffered "extremely low sales" after the coronavirus pandemic forced it to shut some branches.
While SSP operates across more than 30 countries, including the US, India and China, the job cuts are only being made at its UK business.
SSP owns a number of brands including deli operator Camden Food Co. and luxury bar chain Cabin, which has outlets in airports and train stations.