Yorkshire MP Rishi Sunak has been appointed Chancellor of the Exchequer.
Sajid Javid dramatically quit the role on reshuffling day in a row with the Prime Minister over his closest aides.
Allies of the former chancellor said the Prime Minister had ordered him to fire all of his senior aides if he wanted to remain at the Treasury which Mr Javid refused to do.
There have been long-standing rumours of tensions between the ex-chancellor and Mr Johnson's closest aide Dominic Cummings.
In August he had fired Mr Javid's aide Sonia Khan and it appears Number 10 wanted to go further in keeping a closer eye on the chancellor.
Mr Javid said that "no self-respecting minister" could accept the condition being imposed.
Mr Sunak has been Chief Secretary to the Treasury since July 2019. He will take the job having reportedly agreed to a joint Number 10-Number 11 team of advisers.