What would happen if Thomas Cook collapsed?
If Thomas Cook does collapse, the Civil Aviation Authority is expected to launch a major repatriation operation to fly home UK holidaymakers stranded abroad.
Thomas Cook is one of the world's largest travel companies.
It was formed by a cabinet maker of the same name.
Mr Cook organised his first trip in 1841, taking around 500 supporters of the temperance movement on a day trip by train from Leicester to Loughborough.
His first commercial venture was an outing to Liverpool in 1845, before expanding to overseas trips in 1855.
If Thomas Cook does collapse, the Civil Aviation Authority is expected to launch a major repatriation operation to fly home UK holidaymakers stranded abroad.
This will involve hiring aircraft at a cost to taxpayers of millions of pounds.
When Monarch went bust in October 2017, the Government spent #60 million getting passengers home.
Customers who booked a package holiday through Thomas Cook will be financially protected through the Atol scheme.
That means those already abroad will be able to continue with their holiday and an alternative flight home will be organised for them.
Those with future bookings will be offered a full refund.
Anyone who bought a flight-only deal through Thomas Cook is likely to have to contact their credit or debit card provider in a bid to get their money back