@How will these ID cards help?
No no no, you're still assuming that they need to justify anything to you.
We joined Bush's war because we wanted to topple the evil dictator and implement democracy with a longterm plan. Don't you remember? The justification before, during and after can change no matter how disastrous the results.
We know there is no reason for ID cards that benefits us. I can see some reasons why HMRC and councils would love information, and the ability to market it to selected organisations... but I really can't see why they are pushing it so much. Surely HMRC has got better methods of wasting billions, god knows the council are creative enough, so why is it so important. Does it really just come down to one huge gravy train?