The ban on liquids in air passengers’ hand luggage must remain in place and not be lifted next year, say UK airports.

The Airport Operators Association (AOA) argues the new generation of scanners touted to allow relaxation of the ban is “not mature enough”.

The AOA warns airport security queues and delays will grow if liquids are allowed through and it has called on the government to oppose a Europe-wide relaxation.

The European Commission plans a partial lifting of the ban on liquids, aerosols and gels in carry-on bags from April. The ban has been in place since August 2006, following the discovery of a liquid-bomb plot, restricting passengers to carry-on containers no bigger than 100ml.

The EC plans to lift the ban following a partial relaxation for transfer passengers from outside the EU in April 2011. However, that relaxation did not apply in the UK after the government withdrew support for it.

The AOA wrote to transport secretary Justine Greening today, saying: “The ban should not be lifted.”

AOA chief executive Darren Caplan said: There has been testing across Europe since last year, at 14 airports including Heathrow, and it is clear there are the same problems as a year ago [at the time of the partial relaxation].

“The technology is not mature enough. There are too many false alarms. There are problems with flow rates. There is a problem with different rules for different passengers.”

Speaking at a conference on aviation sustainability, growth and security reform in Westminster, Caplan warned: “The ban should not be lifted. Queues will grow longer and get worse [if it is].”

“We have written to Justine Greening to lobby against lifting the ban. We risk confusing passengers if we change the rule.”

The Department for Transport (DfT) recently approved a new generation of airport security scanners designed to detect explosives in liquids and has said it intends “the restrictions be lifted in 2013”.

European transport commissioner Siim Kallas has described retaining the ban as “politically unacceptable”.

However, Caplan told Travel Weekly: “The technology is not good enough. The trials have demonstrated we are not ready. A partial lifting will not work. We have to start lobbying against a partial lifting.”