The number of millionaires in Britain has sunk to its lowest level since the 2008 financial crisis as rich residents flee the country due to punishingly high levels of tax and the removal of non-dom status, a fresh study has claimed.

Figures from the Adam Smith Institute (ASI), a free-market think-tank, found there were 442,000 millionaires in the UK, down by 7 per cent from 2024.

The number of millionaires in Britain has sunk to its lowest level since the 2008 financial crisis as rich residents flee the country due to punishingly high levels of tax and the…