What's the big ID?

The government's ID cards system has been hailed by ministers as the answer to terrorism, benefit fraud and ID theft. At an estimated running cost over the first 10 years of £5.8bn, the system enshrined in the ID cards bill passing through parliament will require every citizen to register personal information on a new national ID database, along with their personal biometrics (iris pattern in the eye, fingerprint and digitally recognisable facial features) to receive an ID card and number, used to prove entitlement or gain access to services, rights and benefits. This is meant to make life simpler, safer and fairer.

What it looks likely to do instead is create new and vicious social divisions and discrimination, which in turn is likely to create new difficulties for the providers of services in the caring and public sectors.

The Passport Office is opening 70 new centres across the country to process the first wave of ID registration at an estimated personal cost of £93. People will be required to travel to centres at their own expense, with the right documents and the money to pay. People who are disabled, marginalised, ill and confused will experience disproportionate difficulties in doing so. Many will simply give up.

The bill allows for this by punishing them. Anyone who fails to keep any registration appointment will incur a civil penalty of £2,500.

The problems do not end there. Iris scanning works very imperfectly, for example, on those with degenerative eye diseases and cataracts, or on brown eyes.

Fingerprints are less reliable: they are likely to be unreadable or unverifiable on manual workers, older people, those with skin diseases such as psoriasis, and many women, especially Oriental women. Facial recognition technology raises problems for veiled Muslim women; it reads odd-shaped faces badly.

There will be registration difficulties for people with Parkinson's, mental, psychological or anxiety disorders, or hearing problems. In a Passport Office trial of 10,000 people, iris registration failed for 39% of those with disabilities. Given the pressing need of service users to have functioning ID registration in order to access essential everyday services and rights, it is reasonable to think that registration will be a fraught and discriminatory procedure for many.

Once registered, the difficulties continue. False positives or negatives are likely to be thrown up regularly by the system: in the trial, nearly a third of registered faces failed to be recognised again by the technology after an interval of 15 minutes. Even the most reliable of the three biometrics, iris recognition, did not work for one in 10 disabled people, and nearly one in 20 of the population.

Those who have to rely more on the card will suffer proportionately more inconveniences. If you are a temporary worker and the ID system pronounces you (wrongly) as not entitled to work, what is your situation? You are barred from working, with no means of redress. All changes of address must be registered, with a £1,000 civil penalty for each failure to do so. Where will that leave the UK citizens who do not know where they will be sleeping next week?

Given that the card will be needed to claim benefits, open a bank account, or get a job or accommodation, it will be valuable. Criminals will see the point. Want to enforce discipline on vulnerable souls? Confiscate someone's ID card, and you've got them.

With so many new registration and data centres, many people will be able to abuse the ID database. Once everyone's movements and actions are registered online, how are people legitimately fleeing within our society going to be protected from those who want to track them down?

For service providers, the ID card system is likely to become a nightmare. Many frightened and confused people will need help. Others will be furious. Service providers will become gatekeepers, with little room for manoeuvre. If the system denies someone their benefit payment or pension, so be it. Get used to it.

Charities are likely to be overwhelmed with extra work helping to steer the most vulnerable through the system. The ID system will massively increase bureaucracy within all public service systems. It will squeeze budgets. The big expense will be the running costs -likely to come out of local budgets.

With so much at stake, so many at risk, and so much potential discrimination and social disruption about to descend on us, you have to ask: is this really the best way to catch terrorists?

· Christina Zaba is a lecturer and a freelance journalist.