There is a real issue with immigration in the UK.

People want actual action on immigration, not gimmicks, not lies. The Conservatives were annihilated because their voters caught up with the fact that they were lying (talking tough while actually pushing immigration higher).

Those Digital IDs would do nothing against illegal immigration considering existing right to work and right to rent legal checks. It is clear and people see it, so see previous point. "you need to prove you’re entitled to work/live here/claim benefits" is already the case and has always been the case. He is copying the disastrous Conservative strategy to talk tough while doing nothing and in fact actually keeping immigration up.

There have been previous attempts to introduce ID cards. People have always been generaly against them and the most against them are probably those already supporting Reform UK or the libertarians on both sides. So he's only eroding the little support he has left (progressist liberals) while strengthening the opinion of those already against him. I was looking at the readers' comments on The Guardian and there are overwhelmingly opposed to the proposal. So if even them turn against Starmer he is well and truly toast.