Goldman Sachs and Deutsche Bank have kicked off the latest exodus from the City by telling staff not to come in once the new national lockdown rules come into force on Thursday.
In a memo to its 5,000 London staff Goldman's international boss Richard Gnodde said only those who have been told they are “in-office essential” can come in from Nov 5, when strict measures come into effect after a rapid rise in coronavirus cases.
Deutsche Bank, one of the biggest employers in the City with 8,000 UK staff, told its bankers that the "majority of those currently spending time in the office will be asked to work from home" from Thursday although said it would like to see most people stay at home from Tuesday.
Goldman was one of the banks encouraging people to return, recently bringing in free coronavirus tests for employees so they felt comfortable coming back.
However, confidence may have been knocked last month after some staff received positive test results and their colleagues were sent home. Meanwhile, daily infections reached a point that prompted the Government to announce a one-month national lockdown.
Other financial institutions, including Standard Life Aberdeen and NatWest, told workers months ago to stay home until 2021 despite a plea by ministers for people to get back to their desks in September.
Those that have reopened their offices have been operating at less than half of capacity due to social distancing rules.
A study by Morgan Stanley in September found that 70pc of office workers across Europe had returned to working at their normal location while only 37pc of those in the UK had done so.
However, by early October almost two-thirds of British workers had returned to the office to some degree, according to the Office for National Statistics (ONS).
The latest lockdown could push more City firms towards making permanent changes to office life.
Schroders is among those to have already told staff they will never have to come into the office five days a week again. JP Morgan and law firm Linklaters have also called an end to the daily commute.
Boris Johnson's announcement of a month-long UK lockdown on Saturday came as the UK surpassed 1m lab-confirmed cases. Cabinet Minister Michael Gove admitted the national lockdown may be extended beyond Dec 2.