It gives me no pleasure to be right on this.
I mean if you have a passport then you already have an 'ID card', but I certainly don't want to take that out with me to prove my age.
My own personal thinking has evolved on the subject since I campaigned against ID cards under Blair ("no2id"). It is a question of trust and purpose. Things like the Estonian digital identity scheme do not seem to be bad in practice. The problem comes from identity checkpoints, which serve as an opportunity for inconvenience, surveillance, and negligence by the authorities.
Remember the "computer is never wrong" Fujitsu scandal? The Windrush fiasco (itself a story of identity and records)?
And anything born of an immigration crackdown is coming out of the gate with a declared intention to be paranoid and authoritarian.
It won't.
The US border is now locked down far tighter than it ever was when I was a kid, and the cries for locking it down even more and violently apprehending suspected violators are at a fever pitch. The UK too - like many countries in the recent rightward lurch - has gone from a country where I can just show up to visit to one when were I need to request permission beforehand.
It sure seems like the "concerns about immigration" in the UK mirror those in the US, which in my analysis is a reaction towards the loss of white privilege combined with the loss of economic power. Putting stricter id checks may assuage abstract xenophobia, but the concrete details don't fundamentally change the concrete details.
It's not like Brexit fixed those concerns about immigration.
If anything, Brexit has exacerbated control over immigration as we can no longer access shared information with e.g. France.
'Opinion polls found that Leave voters believed leaving the EU was "more likely to bring about a better immigration system, improved border controls, a fairer welfare system, better quality of life, and the ability to control our own laws"'
Doesn't seem to have helped, has it?
So a justification based on a premise of alleviating some concerns about immigration has a long historical trail of failures behind it, as I'm sure the Windrush generation can share. The US and Canadian citizens along what was once pridefully called the world's longest unprotected border have also their misgivings.
As I read here, the UK passed the law that required employers to check employee eligibility. I'm sure that was meant to alleviate xenophobic concerns. Why wasn't that enough?