I might be missing something but

rather than messing about with ‘mansion taxes’ and suchlike for expensive homes why don’t the government just make a band I (and J or K if necessary) for council tax?

Because different taxes go into different pots.

here’s a clue, see if you can work it out

council tax

Yes, but must be easier to ask the councils to hand over the extra income from band J, or reduce their grant from central government by an equivalent amount, than to set up a whole new tax?

If they were to do that, they’d have to reassess all the properties in order to see which bands they should all be in. At that point: can open – worms everywhere.

Because then you’d end up with the patently unfair situation of rich people having to pay more for their ever-increasing investments homes.

And that simply isn’t the done thing I’m afraid old chap. Rich people don’t do tax. The poor must bear a completely disproportionate burden of that.

Its the British way!

*swells with national pride*

Because then you’d end up with the patently unfair situation of property-rich, cash-poor people having to pay more for their ever-increasingly valuable investments homes.

Which is the patently unfair situation a great many people who bought houses twent-thirty years ago would find themselves in.
How do you suggest a pensioner, owning a house now worth a couple of million pounds, which cost maybe £100-200,000, finds tens of thousands of pounds a year to pay a tax that these posh politicians wouldn’t need to worry about?