London: Millions of British air passengers face mandatory fingerprinting before being allowed to board flights when Heathrow's Terminal 5 opens later this month.

For the first time at any airport, the biometric checks will apply to all domestic passengers leaving the terminal, which will handle all British Airways flights to and from Heathrow.

The controversial security measure is also set to be introduced at Gatwick, Manchester and Heathrow's Terminal 1, and many airline industry insiders believe fingerprinting could become universal at UK airports within a few years.

All four million domestic passengers who will pass through Terminal 5 annually after it opens on March 27 will have four fingerprints taken and be photographed when they check in. To ensure the passenger boarding the aircraft is the same person, the fingerprinting process will be repeated just before they board the plane and the photograph will be compared with their face.

BAA, the company which owns Heathrow, insisted the biometric information would be destroyed after 24 hours and would not be passed on to the police. It said the move was necessary to prevent criminals, terrorists and illegal immigrants trying to bypass border controls.

The company said the move was required because of the design of Terminal 5, where international and domestic passengers share the same lounges and public areas after they have checked in.

Boarding pass swap

Without the biometric checks, the company said, potential criminals and illegal immigrants arriving on international flights or in transit to another country could bypass border controls by swapping boarding passes with a domestic passenger who had already checked in. They could then board the domestic flight, where proof of identity is not currently required, fly on to another UK airport and leave without having to go through passport control.

Most other airports avoid the problem by keeping international and domestic passengers separate at all times, but the mixed lounges exist at Gatwick, Manchester and Heathrow's Terminal 1. Gatwick and Manchester currently deal with the problem by photographing all passengers as they pass through security, and checking the picture against their face at the departure gate. Terminal 1 will soon introduce fingerprinting.

Civil liberties campaigners have raised concerns about the possibility of security agencies trying to access the treasure trove of personal data in the future, adding that fingerprinting "will make innocent people feel like criminals".

Other countries

There are also fears that fingerprinting will add to the infamous "Heathrow hassle" which has led to some business travellers holding meetings in other countries because they want to avoid the sprawling, scruffy airport at any cost.

Dr Gus Hosein, of the London School of Economics, said: "BAA says the fingerprint data will be destroyed, but the records of who has travelled within the country will not be, and it will provide a rich source of data for intelligence agencies. By doing this they will make innocent people feel like criminals.

"There will be a suspicion that this is the thin end of the wedge, that we are being softened up by making fingerprinting seem normal in the run-up to things like ID cards." Rights activist Simon Davies said a photograph alone would be a perfectly adequate and much cheaper way.