Dominic Cummings has claimed Boris Johnson said wife was driving him “crackers” and he wanted to get her a job “with lots of foreign travel”.
In another public attack on Carrie Johnson, Mr Cummings said he thought she was a “wrong ‘un” from the moment he met her back in 2016.
Mr Cummings claims that Mrs Johnson was at upstairs while texting her husband questions to ask his then chief advisor.
“So when Boris and I came to the break-up in the final few days, we sat on the sofa and he started reading out questions from his phone and I said, ‘Have you lost your mind? Your crazy girlfriend is sitting upstairs texting you questions?
“And he was like, ‘Oh my God, you’re right, she’s driving me crackers. We’ve got to find her a job with lots of foreign travel. Could we get the Cabinet Secretary to give her a job on COP26, travelling round with Kate Middleton?’
The comments come days after Mrs Johnson announced she is pregnant with her second child.
She published a post on Instagram revealing she was expecting the couple’s second baby after suffering a miscarriage earlier this year.
A Number 10 source said claims made by Mr Cummings were “risible, like much of Dom’s recent output.”
They also told the Daily Mail, the claims were “untrue.”
Downing Street were also quick to deny allegations that Mr Johnson had offered Mr Cummings a peerage after he left his role.
The former aide was forced out of Downing Street in November last year following reports that he was leaking damaging information about Mrs Johnson to journalists.
Asked if the peerage would have made him “Lord Cummings of Barnard Castle”, he replied: “No. He said it but then he almost immediately started laughing and realised that that was not exactly the sort of thing that would buy me off.”
Watch: Boris Johnson calls The Telegraph his 'real boss', claims Dominic Cummings