Aircraft hand baggage restrictions imposed after an alleged terrorist plot to attack airliners may be eased, says Transport Secretary Douglas Alexander.
The rules limit the size of hand luggage on aircraft
Mr Alexander told Sky News he was working with airports and airlines on relaxing the rules.
He would lose no time in making changes consistent with security, he said.
The limits on hand luggage have been criticised for causing delays to passengers, and for costing airlines and airports money.
The 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.
Mr Alexander said: "There is an emerging threat in terms of liquid explosives and we have to reflect that in terms of the ongoing arrangements we have in place.
"But we are working very hard both with airport operators and airlines to see if further steps can be taken.
He added: "We have already changed significantly the regime that was in place for the first few days to the regime that is in place at present.
"But if there are further steps that we can take, consistent with security, we will lose no time in putting in place those changes."
Mr Alexander said aircraft security measures were under "constant review".
Leading conductor Mark Elder criticised the restrictions on Saturday because they prevent musicians taking instruments on planes as hand luggage.
Performers faced "enormous difficulty" as a result of the policy, he said in a speech at the Last Night of the Proms at the Royal Albert Hall.
Airports operator BAA is set to announce that the security scare cost it more than £20m.
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.