MPs have criticised government plans for identity cards, warning that while the scheme has the potential to reduce crime, the details are too thin and there are potential risks to personal freedom.

While The Home Affairs Select Committee, which today unveiled its report into ID cards, supported the introduction as a method of improving law enforcement, it warned that the scheme needed tight controls to prevent it forming the foundations of a Big Brother government.

MPs noted that the current proposals lacked "clarity and definition on key elements of the scheme and its future operation".

The report also warned that, without tight controls, there was a danger of a "significant increase to the cost of the programme".

The Home Office proposals have also drawn criticism from privacy campaigners, including Information Commissioner Richard Thomas.

Thomas explained that he remained unsure of the purpose of introducing ID cards, and could not ascertain what limits would be placed on safeguarding the personal data related to the cards.

"As the detail of this infrastructure, and the full magnitude of the proposals, start to emerge, my previous healthy scepticism has turned to increasing alarm," he said in a statement.

And Ian Brown, director of the Foundation for Information Policy Research, added: "ID cards will not tackle terrorism, will not cut fraud and will not reduce crime. The government's plans are an expensive and dangerous folly."

The first ID cards are due in 2007 and the Home Office wants them made compulsory by 2013.

Trials to test the widespread use of biometrics, such as iris scans and facial recognition, are currently underway to see which are most suitable for inclusion in the cards.