Passengers at most major UK airports will be able to carry liquids in containers holding up to two litres in what will be the biggest relaxation of aviation security regulations in decades. The current limit is 100ml.
Travellers will also no longer need to carry the containers in clear plastic bags, or remove tablets and laptops from hand luggage at checkpoints.
The Department for Transport said major airports will be required to install new technology which gives security staff more detailed images of what is in passengers' bags.
It will lay new legislation around the changes in Parliament on Thursday.
Current airport security rules were introduced in 2006 following a foiled terror plot to blow up planes flying from London to the US with home-made liquid bombs.
Travellers failing to adhere to them is one of the biggest causes of delays at airport security.
Transport secretary Mark Harper said: "The tiny toiletry has become a staple of airport security checkpoints, but that's all set to change.
"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.
"Until then, passengers must continue following the existing rules and check before travelling."
The deadline of June 2024 is being introduced after several trials at airports which started in 2018.
The CT scanners create a 3D image of what is inside passengers' bags.
It is already being used at 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."
It comes as airlines were urged by the aviation regulator to “look after their passengers” during Border Force strikes starting next week.
The Civil Aviation Authority (CAA) said travellers should be given food, drinks and overnight accommodation as required if flights are delayed or cancelled, but warned customers were unlikely to be entitled to compensation.
Around 1,000 Border Force staff who are members of the Public and Commercial Services (PCS) union at Heathrow, Birmingham, Cardiff, Gatwick, Glasgow and Manchester airports will strike every day from December 23 to the end of the year, except December 27.
The action is part of a bitter dispute over pay, pensions and jobs.
There are fears that delays in checking the passports of arriving passengers could lead to long queues and even people being held on planes, disrupting subsequent departures.
CAA consumer director Paul Smith said: “We anticipate UK Border Force strikes may lead to longer queues and wait times than normal when arriving at the UK border, as well as possible flight disruption. In the event of delays and cancellations, airlines have an obligation to look after their passengers.”