“Despite claims by other posters, it is well known by economists that the very wealthy tend not to spend into the domestic economy and certainly don't spend enough to keep it afloat. 'Trickle down' is a complete fantasy.”
That depends what you term as the “Domestic Economy”
If you are wealthy you spend on better quality goods wether that is food, clothes, cars or houses that is going to be your main spending, all of which is taxed at whatever level in the UK. If you still have spare cash you invest it maybe a pension or buy to let, even shares all of that is or could be the Domestic economy. What dilutes the trickle down is the amount of goods that are imported into the UK you could buy almost all UK, conversely it could be almost all imported.
You might have a cruise or overseas holiday, most of us don’t have time to do that often, it’s only the super rich that have that choice, even then the travel industry in the UK, benefits from that spending. The amount that is spent directly outside the domestic economy is quite small