Around 5-10% of Pret stores in the UK could close, the sandwich chain's chief executive Pano Christou said in an interview with The Sunday Times.
The group, which has 410 stores and 8,000 staff, is due to outline the scale of job cuts this week. Christou (pictured) said he was having "sleepless nights" about having to tell staff of the impending job losses.
"There's no easy way round this," he told the publication. "It depends come September if the business recovers or not. Clearly we can't keep people on that we would have if business was back at 100%."
Pret A Manger appointed advisers last month to lead rent renegotiations with landlords. Alvarez & Marsal and CWM have been advising the grab-and-go chain on a "comprehensive transformation plan".
At the time, Christou said: "Like the rest of the industry, we have been radically adapting our business model to succeed in the face of the changing market conditions. Reduced footfall, combined with high rental costs, have placed substantial pressure on our business.
"We are putting together a clear plan to address these issues and are already making good progress, with more than 300 shops up and running again as of next week. While Pret may look and feel a bit different in the short term, if we take the right steps today, we'll make sure Pret can thrive in the future and serve even more customers with great food and coffee."