The number of bags containing liquids having to be manually searched after going through Edinburgh Airport 's new 3D security scanners has doubled since the UK government's U-turn on lifting the 100ml limit. Chief executive Gordon Dewar said the "backtrack" decision was "deeply concerning" because of the cost of the new scanners. Edinburgh - Scotland’s busiest airport - has two of the new machines in use, which work like CT scanners in hospitals, along with traditional X-ray machines, to check passengers’ hand luggage for suspicious items.

It has told travellers to stick to the 100ml limit because they will not know which type of machine they will be directed towards when entering security. The airport said the extra manual searches involved “people bringing larger bottles through the new scanners”. The new “C3” scanners have enabled passengers to carry up to two litres of liquids at airports such as Aberdeen and London City , and Edinburgh planned to do the same after its machines are fully deployed by the end of this year.

Electronic equipment will also no longer have to be taken out of bags. However, the government announced in June the 100ml limit, originally introduced in 2006, was being temporarily restored “to enable further improvements to be made to the new checkpoint systems”. The restriction will also be reintroduced at all EU airports from September 1.

Mr Dewar told a meeting of the Edinburgh Airport Consultative Committee this week: “That's not .