In a heated exchange over the redacted Sue Gray report which came out on Monday, the prime minister suddenly took aim at Labour leader, moving the conversation back to when Starmer was the director of public prosecution in 2009.
Speaking in the Commons, Johnson claimed Starmer “used his time prosecuting journalists and failing to prosecute Jimmy Savile, as far as I can see”.
Hitting back at the false accusation the following day, the Labour leader said this claim is a “ridiculous slur peddled by right-wing trolls”.
He also claimed he could see “disgust” in the faces of the Tory MPs when Johnson “debased himself” by bringing up Savile.
Starmer continued: “They knew he was sinking so low with that slur. It’s obviously not true. But he does it because he doesn’t understand honesty and integrity.”
He concluded by saying the prime minister was trying to drag everyone “into the gutter” with his behaviour.
Former Tory cabinet minister Julian Smith who previously worked in Johnson’s government also weighed into the debate on Tuesday, and said it was an indefensible accusation to make.
He tweeted: “It should be withdrawn. False and baseless personal slurs are dangerous, corrode trust and can’t just be accepted as part of the cut and thrust of parliamentary debate.”
Presenter Nick Robinson asked Raab: “The prime minister made an extraordinary and baseless allegation against Keir Starmer yesterday.
“Without parliamentary privilege, would you repeat that allegation against Keir Starmer?”
The deputy prime minister said this is the “cut and thrust” of parliamentary debates and exchanges, but Robinson pointed out: “An allegation that the former director of prosecutions, a man knighted for his work, protected a serial sex offender you’re saying ’is the normal cut and thrust of British politics’?”
Raab still refused to repeat what Johnson said and claimed, “I don’t have the facts to justify that,” before trying to move on.
“No, no no no,” Robinson said. “Does any minister have evidence of what the prime minister said under the protection of parliamentary privilege?”
Raab replied by claiming he had not spoken to every minister, “You can ask me, but I’m saying that I can’t substantiate.”
Robinson added: “So the deputy prime minister cannot repeat words uttered by the prime minister.”
Nazir Afzal, former chief crown prosecutor for the North West, jumped in to defend Starmer too.
He tweeted: “IT’S NOT TRUE. I was there.
“Keir Starmer had nothing to do with the decisions taken. On the contrary, he supported me in bringing hundreds of child sex abusers to justice.”
The fact-checking charity Full Fact also pointed out that Starmer may have been head of the Crown Prosecution Service (CPS) when it was decided Savile would not be prosecuted (due to “insufficient evidence”) he was not the lawyer reviewing the case.
The charity adds: “An official investigation commissioned later by Starmer criticised both prosecutors and police for their handling of the allegations.”
Judging by the Twitter response, Afzal was not the only person outraged by Johnson’s remarks.