The City of London Corporation’s policy chairman Mark Boleat has warned that the City’s international banking workforce could fall by 20% post Brexit.

Speaking at the CBRE Market Insight Series this morning, he cited City UK research revealing that the range of possible job losses as a result of Brexit is 2,000 to 75,000.

However, pressed by Oxford Properties president Blake Hutcheson, who said Canadian banks were telling him they were looking at a circa 20% workforce reduction, Boleat said: “I think that’s a fair assessment for quite a few international banks, yes.”

CBRE researchers said London would continue to prosper because of its resilience, scale, population, innovation and civic design.

In the financial services sector, London is the biggest global market for derivatives traded over-the-counter (49% of market share). London’s foreign exchange market is the largest in the world, accounting for 41% of global turnover, more than New York and Tokyo combined. London also originates more cross-border bank lending than any other country, accounting for 20% of the global market.

Access to the single market, labour and funding were the three key concerns for London’s businesses during the Brexit negotiations, CBRE’s head of central London research Kevin McCauley said.

Grainger chief executive Helen Gordon said her key concerns ahead of the Autumn Statement included the impact of the London Living Rent, land release and stamp duty reform.

Professor Trevor Williams, chief economist at Lloyds Banking Group, said that access to a pool of international talent was vital for the continued prosperity of the capital.

He said: “There’s a reason why London is attractive to so many firms that locate here. It is because they have a talent pool they can draw on that is international in scope. That will be removed if there are restrictions on it.

“And there’s going to be a drip-drip effect. When you begin to notice it, it’s too late. So I think there are some challenges ahead.”