Hmm.
I asked ChatGPT (it's proving useful) what was the combined wealth of the top 1% of wealth holders in the UK. It didn't find a definitive figure, I think because data is sparse, but this was its conclusion:
^ *ONS direct data (more reliable but conservative): top 1% = ~10% ≈ £1 trillion+.^
*Adjusted figures (accounting for underestimation): top 1% could hold 18–23% of total wealth ⇒ roughly £1.8–£2.3 trillion.
It also says
__the most concrete estimate is around £2.8 trillion, held by a relatively small number of high-net‑worth individuals (~685,000), representing 10% of all household wealth in Great Britain.
The top 1% of UK households hold 10% of all household wealth in Great Britain.
On an individual level, around £2.8 trillion (~$3.4 trillion) is concentrated among them.
Each of these households is worth at least £3.1 million.
There is slight confusion between households and individuals here, though I think that the number of households in the top 1% must be more than the number of individuals because a household probably comprises more than one individual.
But, whatever way you look at it there must be a vast amount of under taxed or untaxed wealth in the UK and I cannot see that it would be politically damaging for a government to seek to increase taxes on this wealth. After all, there are millions of people in the rest of the population who would be unworried by such taxation, or greatly approve of it.
And, bear in mind, (referring to my long post earlier) a great deal of this wealth originates from the money that the government 'creates' by spending it into the economy and which inexorably trickles, or, indeed, flows upwards and is not recovered by taxation.