Efforts to push ID card legislation through Parliament for a third time continue to face opposition by those asking for more details on the likely costs and how personal data will be protected.

Yesterday, the House of Lords passed three amendments to the Identity Cards Bill and questioned Home Office estimate that the program would cost £584 million a year.

If it goes ahead, the ID card system would require a massive and robust IT system for checking people's identity and lead to a potentially lucrative cache of long-term vendor contracts. The Home Office says the system would help fight public benefits fraud and banking losses and boost anti-terrorism efforts, among other benefits.

However, a study last year by the London School of Economics (LSE) estimated that the program could cost between £10.6 billion and £19.2 billion over 10 years, far higher than the government's estimates. The school defended the figures in a second report released Sunday.

The House of Lords easily passed an amendment requiring the government to provide additional accounting of the costs, despite the Home Office's insistence that it has an adequate costs study from KPMG.

The LSE and the Home Office continue to bicker, with the school claiming that the government released insufficient information to properly measure the program's costs, and the government saying the LSE's calculation methods are flawed.

Conservative MP Sheila Valerie Noakes, who introduced the cost amendment, said the government has made the ID card proposal "opaque and unsatisfactory". "The ID scheme is surrounded by much secrecy," Noakes said. "We know that the scheme will require large and complex IT systems."

Lawmakers endorsed a second amendment asserting that a reliable and secure method for storing personal identification should be used. The final, third amendment mandates that ID cards can be used only to prevent illegal or fraudulent access to public services.

The Identity Cards Bill calls for a National Identity Register database that would hold personal information, including biometric details such as iris patterns and fingerprints, with records updated at least once every 10 years. The British government envisions as many as 44,000 private-sector organisations such as banks being linked to the system.

The Home Office estimates that issuing a biometric ID card along with a biometric passport would cost £93 per person, with 70 percent of the cost being the passport. The Home Office wants to start issuing cards by 2008 when people renew their passports. It is due to start issuing biometric passports this year.

The House of Lords is scheduled to discuss further amendments to the ID card bill on two more days this month.