Home Secretary David Blunkett took the first steps towards introducing a compulsory ID card in the UK on Tuesday this week.

Launching a new consultation document asking for public opinion on the proposed 'entitlement card', Blunkett spouted assurances that the government would not introduce any such card "without consulting widely and considering the views expressed carefully".

But back in September 2001 he said he had no plans to introduce an ID card, so whether his promise holds much weight remains to seen.

Implementation of such a card is expected to cost around £1bn. If introduced, the card would contain a computer chip with information on entitlement to NHS treatment, education and state benefits.

"We had hoped that the prospect of the government introducing an ID or entitlement card had been quashed last autumn," said Mark Littlewood, director of campaigns at human rights group Liberty. "Not only would such a scheme be prohibitively expensive, but it would impose a real threat to civil liberties."

The problem, according to Liberty, is who would govern what information was held on the card. The Home Office said the card was only in "planning stages" and contents would have to be discussed if and when it was approved.

The introduction of ID cards was mooted after the terrorist attacks in September last year, but the Home Office denied it was considering such a scheme, saying only that "the policy was being kept under review".

But if the system is instigated then the information stored on the cards will have to be kept in some sort of central database.

"The government [has already] conceded that ID cards have nothing to do with combating terrorism," said Liberty's Littlewood. "Once [a national database] is in place there must be a real threat that the system would become over draconian."

The government will also have to convince people their information will be kept safe from hackers, something human rights campaigners and civil liberties groups have said would be impossible to do.

On a positive note, the government has promised it will not be compulsory to carry a card. But people will be obliged to use it for all dealings with the state, including visiting their GPs, dental surgeries or local hospitals.

Under the ID card system currently in place in Germany, it is compulsory to carry the card at all times and failure to produce it on request can result in a 24-hour prison stay.

"People already have countless ways to prove their identity, whether they are using private or public services. It may be wise to review the ease with which such forms can be forged but this does not merit introducing a scheme which would cost hundreds of millions of pounds," added Littlewood.