Asset manager Rathbones has cautioned that the introduction of a wealth tax under a new Labour leadership could precipitate a £100 billion exodus of capital from the UK.
The firm argues that such a fiscal move would be economically damaging, hitting growth, investment, and jobs.
The warning comes as British Prime Minister Keir Starmer has announced his resignation from both the premiership and the leadership of the Labour Party.
This has set off a rapid succession process expected to introduce short-term volatility and uncertainty regarding the party's future fiscal policy direction.
Rathbones' assessment highlights the sensitivity of high-net-worth individuals to potential tax changes.
The prospect of a wealth tax is seen as a significant risk factor for the UK's economic outlook, with the potential for substantial capital outflows if implemented.