By P.R. Venkat Updated Sept. 22, 2019 11:17 pm ET

Thomas Cook Group PLC said it has entered into compulsory liquidation and is now under the control of the official receiver.

The British travel company said it has ceased trading with immediate effect and that all bookings, including flights and holidays, had been canceled. It had said Friday that more than 600,000 customers were on holiday outside the U.K.

That includes more than 150,000 British customers, according to Britain’s Civil Aviation Authority, which said bringing them home will be the largest repatriation in the country’s peacetime history. The process is set to begin later Monday.

“A dedicated support service is being provided by the Civil Aviation Authority to assist customers currently overseas and those in the U.K. with future bookings,” Thomas Cook said on its website. The CAA said it has secured a fleet of aircraft from around the world for the repatriation job, and created a website for Thomas Cook customers seeking information.

Thomas Cook has been under pressure from lenders to find an additional £200 million ($249.5 million) to prevent the collapse of a rescue deal under which Chinese conglomerate Fosun International Ltd. was to inject significant funds. The company, which dates back to 1841, has struggled with a decline in tour and flight bookings, higher fuel prices and uncertainty surrounding Britain’s planned departure from the European Union.

“It is clear that the trends experienced in the first half of the year have continued into the second half, reflecting an uncertain consumer environment, particularly in the U.K., leading to intense competition,” the company said in July.

Write to P.R. Venkat at [email protected]