Shadow levelling up secretary Lisa Nandy said she was "absolutely disgusted" with the prime minister, after he made the discredited claim that Sir Keir Starmer failed to prosecute sex offender Jimmy Savile when he was director of public prosecutions.

Mr Johnson made the remark in exchanges with the Labour leader in the Commons on Monday as he faced MPs in the wake of the release of a partial version of Sue Gray's partygate report.

Victims of Savile, who is believed to be one of Britain's most prolific sex offenders, have urged the PM to withdraw the claim.

Mr Johnson's spokesman has said he "stands by" the comments.

Savile died in 2011, having never been brought to justice for his crimes.

A 2016 report into his abuse found staff at the BBC missed numerous chances to stop him.

Fact check

In 2020, fact-checking charity Full Fact looked into the claim Sir Keir had stopped Savile being charged in 2009, when Sir Keir was head of the CPS.

It said the decision not to prosecute Savile was made on the grounds of "insufficient evidence", with the allegations against the DJ dealt with by local police and a reviewing lawyer for the CPS.

"A later investigation criticised the actions of both the CPS and the police in their handling of the situation," Full Fact found.

"It did not suggest that Mr Starmer was personally involved in the decisions made."

Savile 'slur' a 'new low' for PM

Speaking to Sky News on Tuesday, Sir Keir described it as a "ridiculous slur peddled by right-wing trolls" and he could see the "disgust" on the faces of Conservative MPs behind Mr Johnson as he made the accusation.

"They knew that he was going so low with that slur, with that lie - he had been advised not to do it because it's obviously not true, but he does it because he doesn't understand what honesty and integrity means," Sir Keir said.

And Ms Nandy said the comments were a "new low" for the PM.

She said: "The idea that you would throw lies and mud around in the hope that it would deflect from your own behaviour and your own political problems. And use child abuse victims and survivors as pawns in that game.

"I think this is a new low from the PM and something that I would never have expected to see from the PM of the UK."

Some Conservative MPs have also criticised the PM for his comments.

Simon Hoare, chairman of the Northern Ireland Affairs Committee, said the "false allegation" should be withdrawn.

Tobias Ellwood, who told Sky News he will be submitting a letter of no confidence in Mr Johnson, questioned why the PM made such a remark.

"We're better than this, we must seek to improve our standards and rise above where we are today," he told Kay Burley.

Gove says PM doesn't need to apologise

Also speaking to Sky News on Wednesday, Michael Gove said Mr Johnson had nothing to apologise for.

"I think this is a uniquely sensitive issue and it does need to be handled with care," he said.

"I listen with enormous respect to those who act for victims of the actions of a terrible, terrible criminal.

"But, and it's not a subject that I want to dwell on because it is uniquely sensitive, but it is a case that the CPS apologised for the handling of this case and what happened in 2009.

"I think we should acknowledge an apology was given at the time out of respect."