Airline passengers around the world had grown used to strict 100ml restrictions on liquids, pastes and gels, which had to be put in a clear plastic bag.

But new scanning machines which use CT X-ray technology should in theory enable larger volumes of liquids to go through, and laptops to stay in bags.

Some EU airports, for example in Rome and Amsterdam, had already put them in place and eased their rules. Most had not yet. Some others have been trialling the new technology.

The Europe branch of the Airports Council International (ACI) estimates around 350 of these scanners are now in use across 13 EU countries such as Germany, Ireland, Italy, Lithuania, Malta, the Netherlands, and Sweden.

However, the EU has reinstated the 100ml limit so a technical issue with the new equipment can be addressed, although it has not said what this issue is.

Reports have suggested, external that the scanners were not accurate for some liquid containers being carried in bags.

In July, ACI Europe criticised the restriction as a “setback for the passenger experience and a blow to major investments made by airports”.

Its director general, Olivier Jankovec, said security was the top priority, but added that those “which have been early adopters of this new technology are being heavily penalised both operationally and financially”.

He also argued that restricting their use “questions the trust and confidence the industry can place in the current EU certification system for aviation security equipment”.