European governments have defended plans to fast-track new body scanners into airports despite complaints that the machines invade privacy and amount to virtual strip searching.
With security experts to meet Thursday, the EU was split over whether to use the devices even as the botched Christmas attack on a US airliner raised fears that hard-to-detect bomb-making materials could be smuggled onto planes.
"It is the most reliable instrument," said Italian Foreign Minister Franco Frattini, defending full-body scanners on the grounds they put a premium on safety rather than fan concerns about privacy.
The scanners could detect "if a terrorist has swallowed a capsule full of explosives and could become a human bomb," which would escape a metal detector, the former EU justice commissioner told Radio 24.
Even if the machines meant a "sacrifice" for the privacy of passengers, the "right to security is essential for all other freedoms," he said, as Britain and the Netherlands prepare to introduce them.
But in Britain, privacy campaigners told the Guardian newspaper that the images created by the devices were so graphic they amounted to "virtual strip searching" and have called for safeguards to protect privacy.
Terri Dowty, of civil rights group Action On Rights For Children, said their use could breach child protection laws, which made it illegal to create an indecent image or a "pseudo-image" of a child.
"They do not have the legal power to use full body scanners in this way," she said.
The head of Spain's ASETRA air transport passengers association, Ignacio Rubio said: "Why should a traveller 'undress' in front of a scanner at an airport and not in a train station. Why not the cleaning staff also?"
"Why not use advanced technology that does not invade a person's privacy?" he told the Publico newspaper, and complained that air passengers are tired of "paying the consequences."
In late 2008, the European Commission abandoned plans to have the devices, which see through clothing, introduced at airports across the bloc after European parliamentarians raised an outcry about their use.
A spokeswoman said Monday that Brussels "considers body scanners, if they meet the health standards and security standards, as a useful additional tool providing they do not contradict existing European legislation."
Ultimately though, the 27 EU nations are free to do want they want.
European aviation experts meet behind closed doors in Brussels on Thursday to thrash out a response to the Christmas airline plot in which a Nigerian man allegedly failed to detonate a chemical bomb stitched into his underwear.
"The security committee is going to talk about the consequences of what happened," an EU transport official said on Tuesday, and to see "what each EU member state is doing."
This official said it was "too early" to talk about full-body scanners.
EU justice experts are also monitoring tough new security measures being introduced in the United States to try to stop any similar attacks. President Barack Obama was due to unveil an "initial series of reforms" later Tuesday.
"There has to be a clear transatlantic partnership when it comes to introducing these sorts of measures," an EU justice official said. "We are of course observing what is going on."
Washington has already moved to impose stricter security on flights from 14 nations while random "enhanced" checks will be carried out on all planes landing at a US airport.
Travellers from the targeted countries face extra body pat-downs and advanced screening of baggage. Imaging and explosive detection technology might also be used.
The countries include Cuba, Iran, Sudan and Syria -- all US-designated state sponsors of terrorism -- as well as passengers travelling from or via Afghanistan, Libya, Pakistan, Somalia and Yemen, and Nigeria.
US media said the other four were Algeria, Lebanon, Saudi Arabia and Iraq.