Mr Harrison, former chief of staff to George Osborne, was one of the most influential figures in the previous government. At his leaving party, Mr Osborne joked: “It has been an honour to play a role in the Harrison chancellorship.”
The 36-year-old is joining BlackRock, as chief macro-strategist for funds investing in equities, bonds and cash.
This prompted criticism from John Mann, a Labour MP, who said the “revolving doors” move was “completely inappropriate”. “It is far too soon,” he said. “It is the kind of behaviour that gives politics a bad reputation.” Previous examples of senior figures moving from government roles to private sector positions include Dave Hartnett, who as chief tax collector negotiated the UK’s deal with Switzerland over stolen HSBC files. He later became an adviser to the bank on financial risks and crime. BlackRock has hired top officials before. Mr Harrison was welcomed to the group by Philipp Hildebrand, its vice-chairman, who is a former head of the Swiss central bank. Peter Fisher, a former undersecretary of state at the US Treasury joined BlackRock after leaving government a decade ago.