Limits for carry-on luggage and laptops will not be lifted until June 2024, the UK government announced on Thursday.
The date pushes back ambitions from airports that the restrictions will be lifted next year.
London City Airport has been trialling a security lane equipped with next-generation computerised tomography baggage scanners that it hoped would allow the lifting of restrictions in April.
When restrictions are lifted, passengers at most major UK airports will be able to carry liquids in containers holding up to two litres – up from the current limit of 100ml.
The limit was introduced after a foiled plot in August 2006 to bring down up to 10 passenger planes using explosives disguised as soft drinks.
Major airports will be required to install new technology, such as CT scanners, that gives security staff more detailed images of what is in passengers’ bags, the Department for Transport said.
“The tiny toiletry has become a staple of airport security checkpoints, but that’s all set to change,” Transport Secretary Mark Harper said. “I’m streamlining cabin bag rules at airports while enhancing security.
“By 2024, major airports across the UK will have the latest security tech installed, reducing queuing times, improving the passenger experience, and most importantly detecting potential threats.
“Of course, this won’t happen straight away – this is going to take two years to be fully implemented.”
The deadline of June 2024 is being introduced after several trials at airports, which started in 2018.
CT scanners create a 3D image of what is inside passengers’ bags.
Travellers will also no longer need to carry the containers in clear plastic bags, or remove tablets and laptops from hand luggage at checkpoints.
CT scanners are already in used at some overseas airports such as Schiphol in Amsterdam and several in the US.
Christopher Snelling, policy director at industry body the Airport Operators Association, said: “This investment in next generation security by the UK’s airport operators will provide a great step forward for UK air travel, matching the best in class around the world.
“It will make the journey through the UK’s airports easier and air travel itself more pleasant.”