London - Monarch Airlines went into administration Monday, cancelling flights and holidays as Britain's government worked to bring home as many as 110 000 passengers, according to messages posted on the company's Twitter feed and website.
"We are sorry to inform you that, as of 2 October 2017, all future holidays and flights provided by these companies have been cancelled and are no longer operating," said a message that appeared on Monarch's website under the logo of Britain's Civil Aviation Authority (CAA).
"This is an unprecedented situation and because there are up to 110 000 passengers abroad, the UK Government has asked the CAA to coordinate flights back to the UK for all Monarch customers currently overseas," the message said.
"These new flights will be at no extra cost to you," it continued.
The company's collapse, which came as it failed to have a crucial license renewed, was the largest to hit a British airline, the Press Association reported.
The government's "extraordinary operation" to bring customers home - to include chartering more than 30 aircraft - was Britain's " biggest ever peacetime repatriation," Transport Secretary Chris Grayling said, according to PA.
"This is a hugely distressing situation for British holidaymakers abroad - and my first priority is to help them get back to the UK," Grayling said.
Passengers should expect delays due to the operation, the Transport Department said.
Some 300 000 future Monarch bookings were cancelled, PA reported.
"All Monarch flights from the UK are cancelled, do not go to UK airports," said a post on Monarch's Twitter feed that appeared with CAA and Transport Department logos.