Some £800bn of assets have been transferred from the UK to Europe as financial services firms prepare for Brexit, EY has found.
The figure is based on the public announcements of the 222 largest UK financial services firms and EY has said it was probably a "conservative" estimate.
It covers the staff, operations and customer funds moved from the UK to the European Union as businesses attempt to mitigate the impact of a potential no-deal Brexit.
EY has said the figure was "modest" given the total assets of the UK banking sector alone was estimated to be nearly £8trn but the consultancy has warned the number may grow as Brexit looms.
Omar Ali, UK financial services leader at EY, said: "As things stand, and per regulatory expectations, financial services firms have no choice but to continue preparing on the basis of a 'no deal' scenario.
"The City is further ahead in implementing its Brexit contingency plans than many other sectors and our numbers only reflect the moves that have been announced publicly.
"The closer we get to March 29 without a deal, the more assets will be transferred and headcount hired locally or relocated."
As of the end of November 2018, 80 out of the 222 companies monitored by EY - 36 per cent - had publicly confirmed, or stated their intentions, to move some of their operations and/or staff from the UK to Europe.
For universal and investment banks, wealth and asset managers and the insurance sector, that number jumps to 48 per cent of firms - 68 out of 143.
This includes some 2,000 new European roles which have been hired locally by financial services companies, with Dublin, Luxembourg, Frankfurt and Paris proving the most popular destinations.
Dublin proved the most popular location, with 27 companies confirming they would move or add staff and/or operations in the Irish capital.
Royal London for instance announced yesterday (January 7) that its Irish and German business has been transferred to a Dublin-based subsidiary.