Thomas Cook's future was plunged into further turmoil as stock market analysts declared the company's shares "worthless".
British holiday-makers who have made bookings with the UK's oldest travel company were put on alert when the firm's value tumbled a further 40 per cent.
In the first six months of 2019, the company has already made operational losses of £1.4 billion, chief executive Peter Fankhauser admitted.
Thomas Cook is also labouring under the burden of "heavy debts" of around £1.25 billion.
And the travel giant hit new lows on Friday as analysts at investment bank Citigroup branded their shares "worthless" , advising they should be marked at zero.
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News of the company's problems has caused panic among some of its customers, the Sun reports.
On the Thomas Cook Facebook page , one traveller posted: "I'm flying to Menorca six weeks today. I hope the financial situation will be settled soon."
Another said: "I just booked for next May to Turkey I really hope you're not going into liquidation."
A third wrote: "Are you going into administration? Because I have a holiday booked in October."
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Thomas Cook said that all its holidays are ATOL-protected meaning customers will be able to get a refund if it collapses.
The company has struggled in recent years to keep up with changing habits of customers.
Online aggregator sites, such as Chinese-owned Skyscanner, pose a particular challenge.
Rather than booking through a sole agent, many holiday-makers can now use such sites to scan the web for the best offers on flights and hotels.
The company put their airline business up for sale in February in a bid to raise some much-needed cash.
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Auditors Ernst & Young this week said there was "material uncertainty" around the sale of the firm's airline division.
However, while publishing its half-year results, the auditor said that the company, a British household name, should be able to stay afloat considering all the uncertainties it faces.
In a tweet, the firm wrote: "This announcement has no impact on future holidays or flight only bookings.
"All our holidays are fully ATOL-protected, so customers can continue to book with confidence."
