For me the objections in the UK is not really about the principle (although there are always going to be some privacy/liberty/etc. concerns in that sense), but about the likely implementation.

If we could be assured that whatever was put in place was genuinely privacy/security focused, had open and transparent governance, and wasn't susceptible to capture by corporations/other powerful actors, I suspect many people wouldn't be too bothered. But that's not really the offer, it never is with public IT infrastructure in the UK. The likelihood is that it would be farmed out to one more private corporations to build and maintain, generally for a lowest bid, and overseen by people without sufficient expertise to avert many/any of the potential harms from a poor implementation.

There are good ways to do things like this: public ownership, open governance, security/privacy baked in, all based on a reflective national conversation about trade-offs and the valid fears that many have. What people don't trust is not really the concept of ID cards, it is instead the track record of this and previous governments with both IT and privacy impacting legislation, and even more so the potential inclinations of future governments, particularly at a time when far-right parties are floating ideas like mass deportation of people legally entitled to be here.

Digital ID and a free society are not inherently opposed, but there is no sign that this or other administrations are sufficiently interested in, or aware of, the complexities involved to produce anything other than a semi-permanent disaster.

The COVID NHS APP was open source, secure and excellent?