Pret A Manger plans to cut staff hours by 20% as London and workplaces around the UK remain empty.
The sandwich seller is struggling to survive the coronavirus pandemic and already it has cut workers and closed stores.
Many workers remain at home despite lockdown restrictions being lifted, leaving Central London decimated. UK workers have been the slowest in Europe to return to the office. France, Germany, Italy and Spain have largely returned to normal working practises.
Trade across the country is understood to be down by 65% since the lockdown came into force in late March. In the City of London, business has fallen by 80%.
Pret's strategy before coronavirus was to have as many sandwich shops in and around offices, something that seemed perfectly logical pre the pandemic.
A Pret spokeswoman said: "Our biggest priority is to do everything we can to save jobs.
"With footfall in our shops still significantly below normal levels, we have had to review the hours team members are contracted to work each week - although of course we hope to increase these hours as trade improves.
"By making these changes we are able to save a large number of roles."
Pret is also in talks with landlords about reducing its rent bill. In May, it appointed advisory firms to help restructure the business, and in April it raised €100 million (£90 million) in emergency funding from its banks.
