Boris Johnson has appointed a new chief of staff, Downing Street has announced.

Dan Rosenfield’s appointment follows a period of upheaval which saw the prime minister’s senior aides Dominic Cummings and Lee Cain resign.

Mr Rosenfield has previously worked as a Treasury civil servant under Labour chancellor Alistair Darling and his Tory successor George Osborne.

He will begin work at Downing Street on 7 December.

The current acting chief of staff Lord Udny-Lister will stay in the role until 1 January when Mr Rosenfield will take over.

Mr Rosenfield joins No 10 from Hakluyt, a strategic advisory firm.

He has also previously worked at Bank of America as a managing director and is chairman of the humanitarian agency World Jewish Relief.

The chief of staff role had originally been offered to Mr Cain, however some MPs and ministers objected to the appointment.

And following a power struggle inside No 10 both Mr Cain and his ally Mr Cummings stepped down from their roles.