The Home Office has confirmed that it will introduce iris scanning technology at the UK's busiest airports to bolster immigration controls.

The Iris Recognition Immigration System (Iris) will be installed in two Heathrow terminals by summer 2005.

The government plans to subsequently extend the technology to all Heathrow terminals as well as to other airports, including Gatwick, Stansted, Birmingham and Manchester.

"We need to ensure that our controls are robust enough to let in only those with the right to be here, and efficient enough to process legitimate passengers quickly," said immigration minister Des Browne in a statement.

The Home Office will ask non-European Economic Area residents with indefinite leave to remain in the UK and who travel frequently to register for the scheme. It expects more than a million registrations within five years.

In recent times the government has sought to strengthen border controls through the use of biometric technologies. Last year it announced a pilot scheme to fingerprint visa applicants entering the country from Sri Lanka.

The Home Office has signed a five-year contract with security firm Sagem SA to provide the iris recognition system.