The UK's three busiest airports are set to miss the government's deadline for installing high-tech scanners that will end the 100ml limit on liquids you can take on planes.
Heathrow, Gatwick and Manchester airports have said they do not expect the CT scanners, which will take high-resolution 3D images to check hand baggage for any dangerous or banned items, in place by 1 June 2024.
Gatwick and Manchester airports have said they expect the work to be completed in 2025, while Heathrow has not given a date for when it expects the full rollout across its four terminals to be finished.
The Department of Transport announced the deadline in December 2022, with people allowed to bring up to two litres of liquid onto planes in bags once the scanners are in place.
The move will massively reduce the need for travel-sized toiletries.
The 100ml liquid limit was introduced after a terrorist threat in 2006 and was designed to stop explosives being carried onto planes.
It has required passengers to place their small pots of fluids in a clear plastic bag separate from their hand baggage.
Heathrow has said it is spending £1billion to install the scanners in the 146 security lanes across its four terminals.
A spokesperson has said the transition is "less complex" at smaller airports.
They added that the airport is focused on installing the scanners as "quickly as practically possible" and the machines are already in use in three of its terminals.
They added the scanners will be in all four terminals by the summer of this year.
However, the spokesperson did not give a date for when the full replacement of the machines across all 146 security lanes will be completed.
Meanwhile, London Gatwick says it has made "significant progress" in installing the scanners in both of its terminals.
A spokesperson for the airport added: "We currently plan to have completed the major logistical operation required to install the remaining scanners in (the first quarter of) 2025, after the busy summer peak period has concluded."
The Manchester Airports Group (MAG) operates Manchester, London Stansted and East Midlands airports, with the 100ml liquid limit set to be in place on all three sites after the June deadline.
A MAG spokesperson said the new technology is being installed "lane-by-lane at Manchester and London Stansted airports, with several new lanes already in operation" with the "full completion" of the rollout expected in 2025.
They said in a statement: "We continue to make good progress at all three of our airports on the introduction of new security screening equipment, as part of the UK-wide programme. This is a complex programme of work requiring the expansion of terminal facilities, while at the same time maintaining operations during construction."
It comes after London City Airport scrapped the 100ml rule in April 2023 after introducing the scanners in its security lanes.
Teesside International Airport also already has the scanners in place.
Rory Boland, travel editor at the Which? consumer group, said the fact Heathrow, Manchester and Gatwick are "falling behind" on the June deadline could "create a lot of confusion for travellers about what the rules are for liquids and removing electronics at different UK airports, leading to more delays".
He added: "Airports must ensure they are fully staffed ahead of peak travel periods this year and clearly communicate with travellers about any changes to their security systems and rules to avoid unnecessary disruption."
The Department for Transport (DfT) has said there is a "regulatory requirement" for Heathrow, Gatwick and Manchester to install the scanners before the deadline.
However, the department said it might allow airports "slightly longer" to complete the rollouts across their terminals.
The DfT said in a statement: "The UK has some of the most robust aviation security measures in the world and this cutting-edge technology will enhance security and boost the passenger experience.
"We are in regular contact with airports as they move towards the June 2024 deadline for upgrading their screening equipment and processes. For security reasons don't talk in detail about aviation security measures."