if you are talking about investment banks, there is usually some flexibility with regards to which office a region/ country is covered from (most banks have at least offices in Paris, Frankfurt and Switzerland). For a high earner (£1m + sometimes very much higher), they would probably allow setting up a tiny local office - I have heard that Italy has great tax advantage this days. There will also be bankers covering the Middle East who could be based in Dubai as opposed to in London.
I believe that there would be a similar set up for most finance roles - the WFH culture would most likely allow for working from another country without only certain days in the UK (subject to tax treaty).
with regards to private doctors, I would assume that the highest earners could set up a practice abroad and spend only a certain time in their U.K. practice (subject to tax treaty with relevant country).
for all entrepreneurs- that is easy, they could just take tax advice and set up an office in another country (again, certain time can be spent in the UK but tax needs to be considered).
above a certain annual income, most countries welcome high earners and for example Switzerland, Italy and Dubai have very favourable tax regimes - as does Monaco.
a lot of the high earners are also not born in the UK, so have less attachment to the country. For those with children settled in school here, it would probably depend on how the parents perceive the school relative to international schools. Some parents may decide to have the high earner move abroad (can still spend around 90 days in the UK without becoming tax resident I think), with wife and children visiting every school holiday.
you are talking about highly mobile people. Also quite important to remember that the top 1% pays almost 30% of total income tax, top 5% pays nearly half.
generally, with regards to tax payers, net migration to the U.K. was just about 1 m in 2024. That is a lot of people, especially if you consider housing, GP access and general NHS services. How many houses are Labour building again?
In addition, only the top 40% of households were net contributors to the tax system in 2022. Most migrants are not in the top 40% which means that services are becoming increasingly stretched. If then the top 1% is driven away.., probably not great. But I am not a politician, what do I know 🤷♀️
sorry for the detail, back to VAT