They would have allowed EU travel without a passport, but sadly didn't take off. Initially they would have incorporated driving licenses too - lots of people already carry a driver's license.
Ironically I've of the reasons for not having them, back in the noughties, was because it would target minorities.
Now, the right wing are beying for blood over immigration, national IDs do seems like they would reduce the ability of illegal immigrants to work/collect benefits. Tories left a massive immigration problem, exacerbated by Brexit.
As soon as the bodycams oh so requested by the Left were worn, it became slowly clear who the majority of perpetrators are in Cops vs. Blacks, Antifa, white liberal women... Now the Left's opinion seems to turn against these.