Rachel Reeves has been warned she risks ‘taxing the UK out of existence’ after a string of budget tax hikes caused a mass exodus from the London Stock Exchange.

The Financial Conduct Authority (FCA) set out plans for a new private stock market system this week, in an attempt to encourage more businesses to list in the UK and stop an exodus that may have cost the UK economy £100bn already.

In a consultation document, the City watchdog said the new stock market system, PISCES, tabled by the…