The problem for me is that it fundamentally changes the relationship between the individual and the state.
There was lots said recently about police brutality and how we should be grateful we live where we do, and not in places in the world where people are treated very badly.
Well, yes, that's perfectly ture, but it doesn't come about by just 'being grateful' or hoping it will stay that way - it comes from the populace putting a value on those freedoms.
One of the most significant is that citizens are free to go about their business unhindered by the state unless they break a law. An ID card, which requires the owner give over their 'biometric data' changes that completely.
I appreciate that if someone wants to, there are currently many ways to track someone - but that's the point - if it is deemed necessary, it is already possible, therefore an ID card is simply a tool of control, nothing more.
I have no need for an ID card - I prove my ID currently with household bills and a birth certificate, when I wish to do so. If you desire to have a neat little ID card for multi-purposes, there are already age-schemes and so on which provide that, and you're free to use them.
The cost issue is obscene, but I'm an ideology, magna carta girl, and I will give up my freedom to exist without being fingerprinted when Gordon Brown turns a fetching shade of green and dances outside Buckingham Palace with nowt but tassles on his nipples.