The Swiss banking group UBS says that thousands of its staff in London could be moved abroad after the UK voted to leave the European Union.
UBS chief executive, Sergio Ermotti said that 20-30% of the workforce could be affected, threatening the UK’s position at the centre of the global insurance market.
More than 5,000 people are currently employed by UBS in London, meaning 1,500 staff members may be moved out of the city.
Mr Ermotti said: "We believe that London will continue to be an important financial centre, although maybe not as important as it is today”.
This is the latest in multiple warnings from business leaders regarding the impacts Brexit will have on the UK as a whole.
Earlier this week, Lloyd’s of London chairman John Nelson announced that some of their business could also be forced to move to Continental Europe as a result of the referendum vote if they were not able to access the single market.
Mr Nelson said on Monday that if this was the case, it was “inevitable” that insurance organisations will move business “onshore in the EU”.
The Financial Times predicted that a fifth of investment banking revenues in London will be affected by Brexit due to restrictions surrounding access to the single market. Senior banking executives and advisers estimated that the amount of revenue facing disruption could be around £9 billion at the very most.