In his latest blog post, Cummings claimed "it is deeply, deeply contemptible that not just the PM but senior civil servants have allowed such people to have their reputations attacked in order to protect the sociopathic narcissist squatting in the No 10 flat".
Cummings asserted that these officials "should realise they will have to defend their defence of the sociopath for the rest of their lives" and that "their last chance to escape this shame is to resign over the next 12 weeks".
The PM, who is grappling with calls to step down over the "partygate" row, previously claimed that he had not broken the rules and considered the events as work-related. He also apologised and reshuffled his senior staff following the publication of Gray's initial findings, but made it clear that he intends to "get on" with his job.