The Prime Minister’s official spokesman was asked about calls by some Conservatives, including former prime minister Sir John Major, to install Mr Raab as a caretaker premier until a permanent successor is in place.

The official told reporters: “The Prime Minister is acting in line with convention.

“He remains Prime Minister until a new party leader is in place and the work of government will continue while that takes place”.

Prime Minister Boris Johnson reads a statement outside 10 Downing Street, London, formally resigning as Conservative Party leader after ministers and MPs made clear his position was untenable. He will remain as Prime Minister until a successor is in place. Picture date: Thursday July 7, 2022.

Labour will call no confidence vote in the Prime Minister if Boris Johnson does ...

Downing Street has said there will be more ministerial appointments on Friday and expects “broadly” all vacancies left by the mass exodus of ministers to be filled.

The Prime Minister’s official spokesman said: “We are in the process of making parliamentary undersecretary of state appointments so they will be coming out shortly.”

Asked whether the number of ministers would again reach pre-Tuesday levels, the official said: “I don’t know if exactly the same but broadly.”

The Prime Minister’s official spokesman added: “The Prime Minister set out to Cabinet yesterday … that essentially the Government will focus on delivering pre-agreed policy, delivering on the manifesto commitments.

“It won’t seek to make any large fiscal changes, nor will it seek to unpick previously-agreed policy.”

Boris Johnson is not the problem. He's just a symptom of Westminster's corrupt system – Joyce McMillan

Asked whether the Government would react to situations such as supply shocks and rising energy prices, the official said: “The Government would not seek to do anything on the fiscal side, particularly those that would have significant impact for a future prime ministers.

“Now, a responsible Government does need to react to emerging issues, but I would point out that we do have significant support already in place for the global cost of living pressures that we are seeing, including measures which have not yet been introduced”.

Jeremy Hunt is highly likely to announce his bid to become the next Conservative leader in the coming days according to reports.

A source close to the senior Tory MP, who ran for the leadership in 2019, said that he was “virtually certain” to enter the contest to replace Boris Johnson.

Boris Johnson will not step aside to allow Dominic Raab to be caretaker prime minister