British Prime Minister Boris Johnson appointed Dan Rosenfield, a business consultant and former treasury official, as his new chief of staff on Thursday.

Johnson is reshaping his senior team of advisers following the dramatic departure of Dominic Cummings earlier this month. Cummings was seen as the driving force behind Johnson’s strategy on Brexit and most other policies, and his exit has been billed as a chance for a ‘reset’ for the British leader.

“The Prime Minister has today appointed Dan Rosenfield as his chief of staff,” a statement from Johnson’s office said. He will begin work in Downing Street on Dec. 7 and officially take up the Chief of Staff role on Jan. 1.

Rosenfield joins from Hakluyt, a strategic advisory firm for businesses and investors, where he has been global head of corporate clients and head of the UK business since 2016, the government said.

He previously worked at Bank of America as a managing director of investment banking, and spent over a decade working in the finance ministry where he served as a senior aide to former finance ministers Alistair Darling and George Osborne.