Iris-recognition technology is already being used at other airports

The iris-recognition system is already in use at Heathrow, Birmingham and Manchester airports to speed up entry into the UK for frequent flyers.

Signed-up passengers look into a camera at an automated barrier which recognises data stored on a database, together with their passport details.

Immigration minister Liam Byrne has launched the scheme at Gatwick.

'Quick and secure'

A Home Office statement said: "With nearly 200 people a minute entering the UK through our border controls, the Home Office must ensure Britain uses the latest technology to defend us from the threat of terrorism, organised crime and illegal immigration."

The system would also let immigration officers "concentrate on other priorities", it said.

The biometric technology works by photographing a passenger's iris patterns and storing the data in a database, together with their passport details.

No two irises are alike and the system "quickly and securely" recognises each registered person when they look into the camera, the Home Office said.

Registration for the system is being conducted by immigration staff in departure areas of the terminal.

The enrolment process takes about five minutes and is free.