The boss of Britain's biggest online trading platform has issued the latest stark warning over Brexit as he said the loss of banking jobs to the continent was already doing "long-term damage" to the UK economy.
Chris Hill, the recently appointed chief executive of Hargreaves Lansdown, told the Press Association banking giants were "voting with their feet" on Brexit by pulling jobs out of the City ahead of the UK's divorce with the EU.
He said uncertainty created by the negotiations was the biggest concern among financial services firms and was filtering down to retail investors.
"The big banks are moving people overseas - that's long-term damage to the UK economy," he said.
His comments come after outgoing London Stock Exchange boss Xavier Rolet said earlier this week that more jobs would be lost overseas unless details of a transitional period were agreed by the end of the year.
Major players such as HSBC, JP Morgan and Goldman Sachs have already said they plan to move hundreds if not thousands of UK jobs to the EU after Brexit, when the UK is expected to lose passporting rights for financial services.
Fears are escalating over Prime Minister Theresa May's negotiations and ability to secure a transition as the Government appears to be in a deadlock with the EU over its divorce settlement.
Mr Hill remained tight-lipped on his Brexit stance, but insisted Hargreaves Lansdown was neutral on the subject, despite co-founder Peter Hargreaves being a prominent supporter of the UK's withdrawal from the EU.
Mr Hargreaves pumped more than £3 million into the Leave campaign, while co-founder and former business partner Stephen Lansdown backed Brexit as well, although less vocally.
Mr Hill also joined other investment fund giants in cautioning over the fragility of stock markets amid mounting fears of an impending correction.
Indices in the UK and US have hit new all-time highs in recent days, seemingly oblivious to global political turbulence, with the FTSE 100 in London notching up its record close of more than 7550 in the face of Brexit worries.
Mr Hill said Britain's stock market could "turn in either direction", adding that "any escalation of geopolitical tensions won't help the mood music".
He said: "There is no doubt that the outlook is as uncertain as it has ever been and liquidity is such that negative news can have a significant impact on individual shares."
But he offered some comfort to concerned investors, insisting that "more money is lost by investors not investing than in the corrections themselves".
Mr Hill took on the top job in April, replacing Ian Gorham, who left after seven years at the helm.
He is aiming to steer the Bristol-based group through its "third stage of growth", with plans to tap into other areas of the £2.4 trillion savings and investment pool.
The group, which also has a 100-strong financial advice team, is planning a "soft" launch of its Active Savings cash management service later this year, with a full roll-out in 2018, in what some experts believe will be a transformative move for the sector.
It will add another string to the group's bow, while growth is showing no signs of slowing at its online fund supermarket, which now has nearly one million clients and saw assets under management swell by another 4% to £82 million in the latest quarter.
Mr Hill said technology was key to the group's growth plans, but he stressed his reservations over so-called robo advice, which is taking the financial services sector by storm.
"It's people you're talking to and they're all very different - you have to communicate with people in different ways," he said.
He said the "drop out rate is far too high" among prospective investors, with many put off by a lack of confidence and understanding.
"That's the challenge for us and everybody," he said.