Airports in the UK and across the EU have this year been rolling out next-gen scanners allowing passengers to carry liquids of more than 100ml in their hand luggage, as well as leave larger electronic devices like laptops and tablets in their bags when they clear security.

However, the European Commission in July said airports across Europe would go back to the old rules from 1 September, mirroring a like move by the UK in June. Industry leaders said the changes risked creating further uncertainty heading into the summer.

National press reports suggest the reintroduction was not linked to any specific threat, but owed to a "temporary technical issue". Again, this aligns with the ruling by the UK’s Department of Transport in June, which said its decision to reintroduce the 100ml liquid rule did not relate to a specific threat or risk.

The European branch of Airports Council International estimates there are around 350 next-gen CT scanners in place and in use across more than a dozen EU countries.