Aircraft hand baggage restrictions imposed after an alleged terrorist plot to attack airliners are likely to be eased next week, the BBC has learned.
The rules have limited hand luggage to the size of a laptop bag
Larger bags will be allowed on board, and passengers will be able to take some liquids through security, ministers are set to say on Tuesday.
The government's transport security division is holding talks with the aviation industry on Monday.
The new measures should take effect next weekend.
According to BBC transport correspondent Tom Symonds the government has been trying to find ways to reduce the impact of the security alert at airports and has carried out a series of tests.
Whether the restrictions will be relaxed will depend on the industry, said our correspondent.
"But it is likely airlines will be desperate to get these changes through," said our correspondent.
Larger bags will be allowed along with some liquids - such as toiletries, including toothpaste.
These items may have to be placed in plastic bags so they can be easily examined at security.
Musical instruments will also be allowed on board again, after professional musicians complained the measures were hindering them.
A statement by the Department for Transport said: "The measures we introduced in August were in response to a very real and serious terrorist threat which continues.
"We will be meeting with industry representatives next week to present to them new proposals aimed at lessening the burden on both passengers and operators while allowing us to maintain a rigorous security regime.
"The department will consider the views of industry representatives, other stakeholders and recent EU discussions, and we intend to make an announcement later next week on new regulations, which the industry will implement as soon as possible thereafter.
The limits on hand luggage - brought in last month - have been criticised for causing delays to passengers, and for costing airlines and airports.
The current security measures also ban all liquids except medication essential for the flight and baby milk and liquid baby food, which must be tasted by the passenger.
Thousands of flights were cancelled at Heathrow and BAA's other UK airports after the alleged plot was foiled last month.
Under the current restrictions the dimensions of hand luggage must not exceed 45cm x 35cm x 16cm (17.7in x 13.7in x 6.2in approx), including wheels, handles and side pockets.
The latest move was welcomed by budget airline Ryanair.
"We welcome any move to remove the ineffective measures currently in place and to restore security to the safe levels that apply to all inbound flights arriving in the UK," a spokesman said.
"To do anything less would hand the extremists a victory."
Ryanair announced last month it was seeking compensation of about £3million from the government over airport delays resulting from the increased anti-terror measures.