Re: Not just immigrants
"That's because UK administration is still stuck into the Doomsday Book era. In other countries were the X century ended many years ago, you need a single ID document."
I assume that you're not from these parts or are very young because a few years back when a previous Home Sec wanted to introduce ID cards it very quickly became clear that this was politically unpopular. Even the disk drives used for the pilot scheme had to be destroyed.
We don't like such things. It smacks too much of population control.
By the way, it's the Domesday Book. Same root as "domestic".