More than 100,000 British holidaymakers could be left stranded abroad following the collapse of Monarch Airlines.
The company has ceased trading with immediate effect, becoming the largest UK airline ever to go into administration.
All future bookings have been cancelled and customers yet to travel are being urged not to go to the airport as there will be no more Monarch flights.
There are 110,000 Monarch customers currently overseas and about 300,000 future bookings have been cancelled.
Around 2,100 Monarch employees have also found themselves out of work this morning.
The Civil Aviation Authority (CAA) and the government are putting together a fleet of 30 or so aircraft so those stranded overseas can be brought home at no cost to them.
The CAA has also set up a dedicated website with advice and information for affected customers as well as a 24-hour helpline (0300 303 2800 from in the UK and Ireland, and +44 1753 330330 from overseas).
It said all customers who’ve booked ATOL protected holidays will either be flown back to the UK at no extra cost or, if they are yet to travel, be able to claim a full refund.
Customers whose travel is not protected by ATOL should contact their travel insurer or debit or credit card provider.
“We know that Monarch's decision to stop trading will be very distressing for all of its customers and employees,” said Andrew Haines, the CAA’s chief executive.
“This is the biggest UK airline ever to cease trading, so the government has asked the CAA to support Monarch customers currently abroad to get back to the UK at the end of their holiday at no extra cost to them.
“We are putting together, at very short notice and for a period of two weeks, what is effectively one of the UK's largest airlines to manage this task.
“The scale and challenge of this operation means that some disruption is inevitable. We ask customers to bear with us as we work around the clock to bring everyone home.”
Monarch’s collapse comes just days after Ryanair announced a reduction to its winter schedule, affecting some 400,000 customers.
In all, the Dublin-based airline is cancelling 20,000 flights between September and March.
Ryanair said all affected customers should have received emails notifying them of the cancellations, adding that by the end of this week, 90% of customers will have been issued refunds or found alternative flights.