Jeremy Hunt, Sajid Javid, Grant Shapps and Mr Zahawi all promised to cut the tax burden on Sunday, while Mr Sunak has insisted it would be irresponsible to do so while the UK is still running a large budget deficit.

Ministers who are close to Mr Johnson have publicly denounced Mr Sunak’s track record and warned that he will reverse the achievements of the Government.

Jacob Rees-Mogg told Channel 4: “I will not be supporting Mr Sunak.” He has previously referred to him as “the socialist Chancellor” because of the pandemic spending he introduced.