Some 300,000 claims have now been processed since the process got under way on 7 October, a fortnight after Cook was liquidated. The CAA says work to refund affected passengers will continue over Christmas and into the New Year period.

Claims continue to be submitted, and the CAA has urged any Cook customers yet to make a claim to do so as soon as possible.

The CAA says some valid claims have taken longer to process due to their complexity, while others have required additional information from customers.

CAA chief executive Richard Moriarty said the operation was the largest in the history of the Atol scheme.

“This process has been made more challenging by the complexities of the booking data we have received from Thomas Cook, as well as the additional security checks we have had to include to reduce the risk of fraudulent claims," said Moriarty. "We thank consumers for bearing with us as we continue this programme.

“We will remain focussed on supporting affected consumers and will continue to process claims throughout the festive period. We ask those who have not yet received payment to monitor their inboxes, including their spam folders, in case we need to request further information from them to progress their claim.”

The CAA has also stressed refunds under the Atol scheme apply only to the contents of the package holiday booked by customers – a combination of flights, along with accommodation, car hire and/or hotel transfers.

Any extras not included on passengers’ Atol certificates will not be covered.

The CAA has urged any passengers with Cook flight-only bookings to contact their card supplier. Those with extras booked via third parties should contact the original vendor or supplier, or approach Abta for further support.

The latest figures from the CAA cover the period to the end of Sunday 22 December. The claims process will remain open until 22 September 2020.