Customers of defunct tour operator Thomas Cook have reacted angrily after learning they will face delays in getting refunds for Atol-protected package holidays.
The Civil Aviation Authority originally said all valid claims made on the first day of its refund programme would be paid within 60 days, or by this Friday.
But now it says only two-thirds will be paid on time.
It said it had asked the remaining claimants for more information.
CAA boss Richard Moriarty acknowledged many would be worried about not getting their money back before Christmas.
“We thank consumers for their ongoing patience as we continue to do all that we can to work through the UK travel industry’s largest ever refunds programme,” he said.
“I appreciate that this is a concerning time for Thomas Cook customers who are waiting for their refunds, particularly at this time of the year.”
When Thomas Cook ceased trading on 23 September, anyone who had paid for a future Thomas Cook package holiday protected under the CAA’s Atol scheme was entitled to a full refund.
From 7 October an online refund application system opened, and customers were told the Civil Aviation Authority aimed to pay out within 60 days.
The CAA said it had received 67,000 claims on the first day, and two thirds would be paid by this weekend, bringing the total amount of compensation paid to date to £160m.