The Civil Aviation Authority has warned consumers who want financial protection for holidays to quiz travel agents on whether everything they are booking is ATOL-protected.

It estimates 18 million people will build their own holidays this summer, booking flights, accommodation and other components with different companies.

A CAA spokesman said: “Many people won’t realise they only get comprehensive protection if they book with an ATOL-protected tour operator, otherwise their money could be at risk if one part of their itinerary goes wrong.”

The warning comes after the failure of CT2 parent HCCT Holidays just before Christmas, with 1,000 people abroad and 40,000 booked to travel. The CAA organised flights home and refunds at no cost to those affected because the company was ATOL-protected.

The CAA said: “The failure highlighted the value of ATOL protection. If consumers prefer to put something together themselves, they should think about other protection. But be careful – many insurance policies do not automatically cover insolvency.”