Director of communications Jack Doyle confirmed his exit shortly after the departure of policy head Munira Mirza. No 10 confirmed both resignations and thanked them for their work.
Ms Mirza left over the PM’s false claim that Sir Keir Starmer failed to prosecute Jimmy Savile when he was director of public prosecutions. Mr Doyle had told staff that “recent weeks have taken a terrible toll on my family life”.
The top aides’ resignations come as Mr Johnson faces increasing questions over his leadership from within his own party.
The BBC is aware of 17 Tory MPs who have submitted letters of no confidence in the prime minister, with a total of 54 needed to trigger a leadership contest.
Many have cited the PM’s participation in parties at No 10 during Covid lockdowns as their motivation to challenge Mr Johnson.
But some have also pointed to his remark about Sir Keir, including senior backbencher and Defence Committee chair Tobias Ellwood.
On Monday, Mr Johnson accused the Labour leader of spending “most of his time” as director of public prosecutions (DPP) “prosecuting journalists and failing to prosecute Jimmy Savile”, despite having no evidence to back up the claim.
Disc jockey and TV personality Savile was revealed to be a serial sexual abuser after his death in 2011, having attacked hundreds of women and children at various locations including hospitals, schools and the BBC.
By Thursday, Mr Johnson appeared to have backed down, telling reporters he had not been talking about Sir Keir’s “personal record” when he was DPP, adding: “I totally understand that he had nothing to do personally with those decisions.”
Asked what he thought of his boss’s comments, Chancellor Rishi Sunak said: “Being honest, I wouldn’t have said it, and I am glad that the prime minister clarified what he meant.”
And asked if Mr Johnson should apologise, he said: “That’s for the prime minister to decide.”
