The Government body responsible for issuing refunds to Thomas Cook customers has issued a public apology for delays that could leave people waiting until the New Year.
The Civil Aviation Authority (CAA) said it is "very sorry" for the delays caused, adding it's "working tirelessly" to process payments.
Despite £160million having already been refunded, .
Thomas Cook collapsed on 23 September, after failing to obtain £200million in rescue funds from its banks.
As a result, some 150,000 travellers had to be repatriated back to the UK during a two-week operation run by the CAA.
Two weeks after its collapse, the organisation then opened its refunds process - asking customers covered by Atol-protected insurance to submit their claims online.
It said all refunds would be processed within 60 days - or by December 6 at the latest.
However, on Friday, it said just two-thirds of claims had been dealt with - .
Paul Smith, director at the Civil Aviation Authority, :said: "This is the biggest refund operation in UK travel. We have paid out already about £160m, and expect over the next couple of days to get that up above £180m.
"We have had to put some extra checks in because we were concerned about fraud. And we had some challenges with the data we received from the company. We are sorry for those people we have not yet been able to pay.
"We really want to make these payments as quickly as we can because it is money people are entitled to," he added.
Some 300,000 Thomas Cook claims have been received so far, 215,000 of which have been confirmed as valid. However, this figure includes about 90,000 direct debit customers in October whose money was automatically returned.
