A major Tory donor has suggested Boris Johnson’s premiership is past the point of no return and criticised the “lack of honour” in modern politics.

       Financier John Armitage said he thinks leaders should quit if they lose their “moral authority”.

       The intervention from Mr Armitage, who has given more than ￡3 million to the Conservative Party came as Mr Johnson sought to reset his administration with a limited ministerial reshuffle and a shake-up of how No 10 operates.

       The Prime Minister is battling to maintain his position in the face of Tory unrest over the partygate row about gatherings in No 10 during the coronavirus lockdowns.

       Mr Armitage has donated more than ￡500,000 to the Tories since Mr Johnson became Prime Minister, but he has also given money to Labour, including ￡12,500 in March.

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       He told the BBC: “What do I think about what’s going on in 10 Downing Street?

       “Look, I feel politicians should go into politics to do good for their country. And that is the overwhelming reason to be in politics.

       “I don’t think it’s about your own personal sense of getting to the top of a snakes and ladders game.

       “And I feel that, if you lose moral authority, and if you do things which… the average person – your mother, someone you try to explain to, someone who you admire – if you do something or say something, which on the front page of the Sunday Times looks terrible, and you do that consistently, and you betray a sense of not really caring, I think you should leave.

       “And I find the lack of honour inherent in modern politics incredibly distressing.”

       Mark Spencer is now Commons Leader following the reshuffle (Aaron Chown/PA)

       (PA Wire)

       Asked if he thinks Mr Johnson’s leadership is past the point of no return, Mr Armitage said: “Personally, yes.”

       Mr Armitage, co-founder of hedge fund Egerton Capital, suggested that Mr Johnson’s attempts to change his administration are not enough to win back support.

       “What about a sense of personal responsibility? You know ‘I’m going to change my chief of staff and it will all be fine’. Oh, really?”

       The BBC said Mr Armitage has told the Conservative Party he will not be giving it any more money as things stand, but he plans to remain a member.

       In response to Mr Armitage, a senior Downing Street source insisted that the Prime Minister remains “entirely focused on delivering for the British people”.

       Boris Johnson will face MPs at Prime Minister’s Questions (Tom Nicholson/PA)

       (PA Wire)

       Mr Johnson will face MPs in the Commons on Wednesday after carrying out a limited reshuffle which saw Mark Spencer moved from chief whip to Leader of the Commons, with the previous holder of that role, Jacob Rees-Mogg, becoming Minister for Brexit Opportunities.

       New Chip Whip Chris Heaton-Harris told BBC’s Newsnight: “I would like to think we have a very strong Prime Minister who is going to continue and get stronger and stronger and lead us into the next election, which we will win comfortably.”

       Mr Spencer’s continued role in Government has raised eyebrows as he continues to be investigated over his role in MP Nusrat Ghani’s allegations of Islamophobia.

       Mr Johnson asked the Cabinet Office to “establish the facts” regarding the Tory MP’s claim that she was told by a whip her dismissal as a minister in 2020 was because of concerns about her “Muslimness”. Mr Spencer identified himself as the whip but denied her accusation.

       Sherwood MP Mr Spencer told BBC Radio Nottingham he had to stay quiet while the investigation – being carried out by Lord Geidt, the Prime Minister’s adviser on ministerial interests – was carried out.

       “That investigation is ongoing… we wait for the results of that.

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       “If I’m honest with you… that is a bit rough, when you’re accused of something of that nature. It’s a bit rough not being able to defend yourself until the results of that investigation come forward.

       “I’ve just got to keep my mouth shut, present the facts to Lord Geidt who’s doing the investigation, and then once that’s concluded, I think we’ll be able to have a fairly open conversation about that.”