Supporters of Liz Truss have expressed fury over the lengthy delay before the new prime minister formally enters Downing Street.
Ms Truss defeated her rival Rishi Sunak to win the Conservative leadership contest, albeit by a slightly narrower than expected margin.
But she has to wait until Tuesday to take over in No 10, despite the cost of living crisis facing the country.
Ms Truss will officially be asked to form a government tomorrow on a visit to the Queen at Balmoral, in Aberdeenshire.
She will then fly back to London where she is expected to give the customary address to the nation on the steps of Downing Street in the late afternoon.
One former cabinet minister who supported Ms Truss criticised how the Conservative party organised the leadership contest. He said: “It is obvious it went on too long. But it is not even over yet. We have built up public expectation on this and now she not back in Downing Street until quite late on Tuesday?”
Another Tory MP said: “The result could have been declared on Sunday afternoon. There is not really any reason why it had to be like this. It is out of touch with the public mood. “
The announcement of the victor was made by the chairman of the 1922 committee of Conservative backbenchers, Sir Graham Brady.
But friends of Mr Brady said the timetable for the election and the announcement of the winner had been decided by the Conservative Party board, not by him.
Mr Johnson is expected to make a farewell speech outside No 10 at around 7.30am on Tuesday before he leaves Downing Street for the last time.
He and Ms Truss will travel north on separate planes, understood to be for security reasons, before they each have an individual meeting with the monarch.
Ms Johnson’s audience with the queen is expected to start around 11.20am, with Ms Truss due to arrive at Balmoral Castle at 12.10pm. After around 30 minutes, Ms Truss will then expected to fly back to London, where she will make her speech at around 4pm.
