IT industry experts today warned that the UK government's latest plans to introduce biometrics-based national ID cards rely on untested technology, and could be stymied by a growing range of technological and operational issues.

Analyst firm Butler Group noted that the government seems determined to push forward with its plans, despite a chorus of IT and privacy objections.

"The government seems to think that because appropriate technology exists it can be shoehorned into supporting whatever scheme it chooses," said Andrew Kellett, senior research analyst at Butler Group.

"Of major concern with the national ID card project is the technology, which has been chosen before all the requirements and alternatives have been fully investigated. But it is the operational practicalities that are of most concern. "

According to Butler Group, there are "at least four main issues" which must be addressed before the scheme should be allowed to move forward: cost, technology, privacy/continuity and scalability.

The analyst firm warned that the provision of biometrics greatly increases costs, not just of card production and the need for specialist readers, but in registration and systems support requirements.

It pointed out that estimates of the cost of the scheme have rocketed to around £19bn.

Kellett accepted that the biometric technology behind the proposed ID card scheme has the potential to deliver secure authentication capabilities. However, he warned that "it is not proven at anything close to the levels of usage and accuracy that are going to be required to support the national ID card scheme".

"Biometrics is still an emerging technology with worries about rejection rates. In a recent pilot only iris scanning reached close to 100 per cent accuracy, and concerns have been raised that people with disabilities could be further disadvantaged," he said.

Kellett added that biometric technologies will do nothing to counter fraud at the point of issue. He also poured scorn on the government's "unrealistic" argument that the scheme would thwart terrorists, asylum seekers and identity thieves.

The use of biometrics on this scale has never been attempted, Butler Group pointed out, and any experienced IT professional appreciates that one of the fundamental prerequisites of any project is to ensure that the requirements are fully documented and understood before designing a system.

An additional concern voiced by Kellett centres on the government's plans to hold personal information on a central database, giving rise to unease about who will be allowed access.

"The government seems indifferent about the creation of yet another central database with yet another identification number," he said.

"It seems to have little or no understanding of the issues involved in keeping such a critical information source up-to-date.

"The increased cost of including biometrics on a card has yet to be justified, and the practical supporting issues are horrendous.

"Just for a start they must include local registration and scanning equipment costs, and the mechanics and support costs of managing the service. This is yet again a case of the government trying to run before it can walk."