LONDON — Anxious holidaymakers who purchased vacations with collapsed UK tour operator Thomas Cook will have the safety net of the "ATOL guarantee" to rely on.

British travel companies are required by law to hold an Air Travel Organizer's License (ATOL) under a scheme which is based on a European Union directive.

The ATOL guarantee scheme is managed by the Civil Aviation Authority (CAA) and covers tourists who have purchased all-inclusive trips with flights and hotels.

British tourists remain protected despite the nation's looming departure from the EU at the end of October.

The CAA has vowed that everything will be done to bring back the more than 150,000 Britons currently stranded abroad, in the UK's biggest repatriation since World War II.

Customers already on vacation with Thomas Cook will be able to finish their stay and return on the scheduled date via a different airline.

Holidaymakers who have yet to leave will be refunded or offered alternative vacation plans.

"Hundreds of thousands of holidaymakers affected by the collapse of Thomas Cook will be incredibly worried, especially if they are currently still on holiday and stranded abroad," said Adam French at British consumer organization Which?

"The good news is that ATOL protection will mean they will be flown back home free of charge.

"Customers who have already paid and booked for an upcoming holiday with the collapsed travel operator should also be entitled to a refund as part of the scheme."

The government's Department of Transport expects that the cost of the repatriation operation will stand at about £100 million (113 million euros, $124 million).

Travelers who have only purchased airline tickets from Thomas Cook are not covered by ATOL — but they can turn to their credit card provider or insurers for refunds.

The European Package Travel Directive also applies to package holidaymakers who booked in other EU countries, guaranteeing refunds and repatriation in the event of bankruptcy.

In total, around 600,000 passengers are currently stranded abroad while on vacation with Thomas Cook, according to a company spokesman.

"Thomas Cook is a global business and a European business," said Dr. Steven Truxal, a specialist in aviation law at City University, London.

"It is affecting not just UK holidaymakers but lots of European holidaymakers who have booked elsewhere."

He told AFP: "There is harmonization because of EU law with respect to package travel.

"The package travel directive ... requires each member state to have in its national law protection for holidaymakers who have booked package travel.

"Package travel holidaymakers are the most protected under European law," he concluded. — AFP