'When young and ambitious people are voting with their feet and leaving your country, that's a shameful sign,' the Shadow Business Secretary said

Britain's millionaire population has shrunk to its smallest size since the 2008 financial crisis, a new study has found.

The Adam Smith Institute found that just 442,000 adults in the UK held net assets of £1million or more in 2025.

That represents a seven per cent fall compared with the previous year, and a collapse from the peak of 1.07 million people in 2021.

The think tank's "millionaire tracker" draws on Office for National Statistics data and counts total wealth including property, pensions, savings and investments.

The number of millionaires has sunk sharply every year for the last four years.

Rising interest rates since the pandemic have eroded the value of net assets, the think tank said, which has only been compounded by falling savings rates offered by banks.

The think tank's tracker uses "constant prices" to strip out the effects of inflation and currency fluctuations.

The ONS only surveys household wealth every two years, so no official count of individual millionaires exists.

The most recent ONS data puts the number of households worth more than £1 million at 3.7 million, driven largely by property price growth.

The millionaire count first crossed the one million threshold in 2020 before climbing to its peak the following year, after which it fell steeply in four consecutive years.

The Adam Smith Institute's report also warned wealthy individuals are leaving Britain or choosing not to relocate here.

In its report, the think tank said: "There has [also] been a well-documented trend of high net-worth individuals either leaving Britain or no longer choosing to move here.

"Millionaires are leaving the country for a number of reasons, including the abolition of non-dom tax status, high levels of general taxation, and a hostile culture for wealth creators."

Shadow Business Secretary Andrew Griffith said: "Whatever their personal finances, everyone should care about Britain having fewer millionaires to contribute to the tax pot and creating jobs and businesses here.

WEALTHY BRITONS - READ MORE:

"It's a competitive world and when young and ambitious people are voting with their feet and leaving your country that's a shameful sign."

The oft-cited 2025 Henley Private Wealth Migration Report claimed a "great wealth flight" was underway, consisting of 142,000 migrating millionaires.

But this year's edition admitted other studies found that "departure rates among high earners were modest and concentrated in specific circumstances".

HMRC figures, meanwhile, do not back up claims of a mass exodus of non-doms from the country.

In the tax year ending April 2024, 60,700 residents were registered with a permanent home abroad.

Non-dom status was officially abolished in April 2025, having previously shielded certain UK residents from domestic tax on overseas income.

A replacement scheme now exempts foreign earnings for up to four years for newcomers or those returning after a decade away.

The Adam Smith Institute has now urged Andy Burnham to scrap inheritance tax and reduce capital gains tax rates.

HMRC data shows roughly 31,500 estates - about 4.5 per cent of deaths - fell victim to inheritance tax in the year to April 2023.

Capital gains tax currently stands at 18 per cent for basic rate taxpayers and 24 per cent for higher earners.

The Prime Minister's allies have pushed him to align capital gains tax with income tax bands of 20, 40 and 45 per cent.

So far, Mr Burnham has said he will "look in detail" at equalising rates, and while he has made no policy commitment, he has floated replacing inheritance tax with a "care levy" to fund social care.