When Japan’s Daiwa Securities heard the British prime minister pledge on October 2 to prioritise controlling immigration in the coming Brexit negotiations, it didn’t wait to act.

The next day, staff accelerated contingency planning for the bank's London investment banking unit and began to contact other European cities, according to a person familiar with the matter. While Daiwa doesn't have a definite plan yet, it could involve relocating some operations to the Continent, and recent events are adding to the pressure.