http://www.theregister.co.uk/2004/11/16/idcard_cost_fiddles/
"The Home Office's objective for the ID scheme doesn't actually have a great deal to do with the kinds of ID card and passport you either want or will get, and rather more to do with what it thinks you'll put up with paying. The money extracted goes towards what they really want - the National Identity Register (NIR). The primary goal of the scheme is to collect biometric and personal data on the entire population of the UK in order to build the NIR, and to use this together with your biometrics as a security and validation system. Cards and passports are merely a recruiting mechanism for this system, the most obvious and immediate example being passports, where you're going to have to co-operate sooner or later if you ever want to leave the country. It is therefore convenient from the Home Office's point of view that all your biometrics, rather than just the ones needed for passports, are collected when you apply for your new passport, because it's the quickest and surest way to get them all.
The real requirements Note that the Home Office doesn't need to do that, and that the National Identity Register doesn't need to be built as a consequence of what the Home Office does have to do. The ICAO international passport standard which will shortly be essential for travel to the US simply requires a biometric facial image, while new European standards whose introduction the Home Office itself supported will also require fingerprints on passports within the next few years. But the NIR is not a requirement. A chipped passport will be much harder to forge, while a biometric passport can be tied relatively easily to the bearer via a local check - no network or NIR required. That's the intent, and that's pretty much what more sensible countries will be doing. You could even throw away the biometrics after you'd put them in the passport, and you'd still have a pretty solid validation system for ports of entry."
