The number of job openings in London for banking professionals has slumped almost 40pc in the past year as financial services firms weigh up hirings in a volatile pre-Brexit environment.
International recruitment group Morgan McKinley also said that 28pc fewer professionals in the city are currently looking for new roles compared to this time last year.
Even compared to November, there's been a stark decline in hiring activity among professionals, as Brexit negotiations between the UK and the European Union come to a head.
Month-on-month, there was a 14pc decrease in the number of finance professionals seeking jobs and a 4pc fall in the number of jobs available, according to the December employment report from Morgan McKinley.
Morgan McKinley managing director Hakan Enver said the deal proposed by Prime Minister Theresa May wasn't detailed enough for the UK's financial services industry.
"The proposal was notably light on details pertaining to the future of the financial services industry," he said.
"It's stunning to see that in a 585-page plan for Britain's future, an industry that contributes £119bn (€131bn) a year to the economy, barely gets a mention," he said.
"In November of 2017 jobs were up by 5pc from the previous month, and only down by 3pc from the previous year. Brexit has taken a considerable bite out of banking jobs and with an ambiguous Brexit deal on the table, the City's bracing for more pain ahead."
The recruitment boss said that in a post-Brexit world, London will continue to be a magnet for professionals seeking career advancement.
But financial services employers still want visa regulations for highly-skilled individuals eased, he insisted.
"If visa regulations aren't modernised, the government will shrink the City's talent pool, effectively shrinking the economy," he claimed.
Mr Enver said that the UK needs to "dust itself off" and "go boldly into a post-EU future".
"That means renegotiated trade deals, and passporting agreements with nations beyond Europe," he said. "There is no rule that says we either have to do business exactly the same way we did five years ago, or do no business at all."
Dublin is among the cities that vied for jobs moving from London.