I have no idea what you're trying to establish here. When Tony Blair proposed mandatory ID back then it was just as controversial and the response was pretty much as we are seeing now. It's a pattern of support dropping after an announcement and public scrutiny which is consistent in the UK every time a scheme like this gets proposed, the same thing happened with proposed vaccine passports.Polling is representative of the mainstream, that is literally the point of it. They specifically account for the politically engaged.
Ultimately I can’t find any polling data following the announcement under the Tony Blair government so I can’t collaborate your assertion either.
At best I can see some anecdotal contributions from partisan media outlets which you have to take with a pinch of salt.
The evidence points towards the previous scheme being scrapped for political reasons, not that a majority of people were against it.
Ultimately it was a scheme which a previous administration implemented, and the new administration opposed it. They were also embarking on a massive austerity drive, the scheme has an ongoing cost and wasn’t fully embedded (e.g. it could be canned with no dependencies). It was a pretty easy target.
If you think it is just because people don't like starmer then so be it.
