The world’s oldest travel firm has entered compulsory liquidation.
Thomas Cook has ceased trading after the firm failed to secure rescue funding.
Hundreds of thousands of bookings have been cancelled and 2,000 staff worldwide could now lose their jobs.
The collapse has triggered the biggest ever peacetime repatriation, aimed at bringing more than 150,000 British holidaymakers home.
The British government has chartered 45 jets which will be used to fly 64 routes today, in an undertaking dubbed Operation Matterhorn.
Operators including easyJet and Virgin Atlantic have supplied some aircraft, with planes coming from as far afield as Malaysia.
The repatriation programme will last two weeks.
According to reports, some hotels have demanded that guests who were about to leave pay extra money, for fear it wouldn’t be paid what it was owed by Thomas Cook.
“I would like to apologise to our millions of customers, and thousands of employees, suppliers and partners who have supported us for many years,” Thomas Cook CEO Peter Fankhauser said.
“This marks a deeply sad day for the company which pioneered package holidays and made travel possible for millions of people around the world.”
In May, Thomas Cook reported a £1.2 billion net debt in its half-year results.
Higher fuel costs and the uncertainty surrounding Brexit are blamed for the collapse.