A billionaire donor to the Conservative party has suggested that Boris Johnson should resign, saying that the prime minister was “past the point of no return”. John Armitage, co-founder of the hedge fund firm Egerton Capital, who has given £3.1m to the Conservatives, including more than £500,000 since Boris Johnson entered No 10, told the BBC he thought leaders should leave if they lose their moral authority. He added: “I find the lack of honour inherent in modern politics incredibly distressing.” Armitage said he had told the Conservatives he would not be giving the party any more financial support as things stood. The financier has also given much smaller amounts of money to Labour, made individual donations to the former Labour MP Frank Field, and contributed to the remain campaign in 2016. A Conservative spokesperson told the BBC the government remained “fully focused on delivering for the British people”. Armitage’s intervention comes after a torrid period for Johnson with an investigation by the senior civil servant, Sue Gray, into parties held at Downing Street and Whitehall during Covid lockdowns finding “serious failures of leadership”. A police investigation is looking at the most serious allegations within the “partygate” scandal and in the meantime Johnson has endured a series of resignations from senior officials, some of which he has sought to replace. Armitage told the BBC global challenges to the west required ‘‘very serious, engaged politicians with a sense of purpose”. “Politicians should go into politics to do good for their country,” he added. “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.” Asked by the BBC’s political editor, Laura Kuenssberg, if Johnson was “past the point of no return”, he replied: “Well, personally yes.” On Wednesday, the health minister, Ed Argar, indicated Johnson would not apologise to Starmer for his remarks about Jimmy Savile, despite the Labour leader being harassed by a mob of conspiracy theorists near parliament on Monday, some of whom yelled “paedophile protector” at him. Asked if the Johnson would say sorry for the jibe, Argar told Sky News: “The prime minister … has been very clear – he’s clarified what he was talking about. “I know colleagues of mine have been on (and) had this conversation with you in recent days. He’s clarified that he was talking about Sir Keir in the context of his leadership role at the CPS. Just as, quite rightly, Sir Keir holds him to account for his leadership role over the government. “That doesn’t mean personal responsibility for individual decisions, but that’s the context, and the prime minister has clarified that. And I’ll be honest with you, I suspect that’s what you will hear from the prime minister later.”