When the full body scanners go on trial next week at Heathrow airport, passengers will not have the choice given in America to have a pat down as they will be required to use the scanners or not fly at all. The UK’s Equality and Human Rights Commission strongly advises against this as they consider it an invasion of privacy.

The airport’s owner, BAA, is preparing to install a scanner in each of its five ­terminals. The trials will use two different technologies that see through passengers’ clothing. One trial will involve “backscatter” technology, which exposes travellers to low-level x-rays. This is already in use at Manchester airport.

The second type of machine uses a “millimetre wave” system, which bounces radio waves off the human body to form a 3D image of the passenger. Both types of technology have raised privacy concerns owing to the graphic nature of the passenger images, with civil liberties campaigners calling the process “virtual strip-searching”.

The Department for Transport has drawn up a preliminary code of conduct for using the machines, and it will follow some guidelines used in the US. These state that the security officer guiding the passenger through the machine never sees the image, and that the employee viewing the scan must be based away from the passenger, in a secure room. The two officers communicate with wireless headsets; and, once viewed, the scan cannot be saved, printed or transmitted.

Virtual strip searches are never a good idea, especially when we now know that these images can be saved. The full body scanners will almost certainly break child porn laws in the United Kingdom as well.