MP Alistair Carmichael has urged Prime Minister Boris Johnson to withdraw and apologise for his comments relating to Sir Keir Starmer and Jimmy Savile.
Mr Johnson had accused Mr Starmer of “failing to prosecute” the dead sex offender – a case Mr Starmer was not personally responsible for during his time at the head of the Crown Prosecution Service (CPS).
On Monday night Mr Starmer was targeted by a mob of angry protestors, who shouted about Savile as they did so.
The prime minister condemned the scenes, but stopped short of apologising for his remarks last week.
Mr Carmichael said Mr Johnson “must withdraw his shameful slur now, with no further qualification or mud-slinging”.
“When the leader of the opposition is being attacked by a mob citing the prime minister’s words, there has to be a reckoning,” he said.
“It has festered long enough – we risk long-term damage to our political culture unless there is a meaningful break from the prime minister’s toxicity.
“He must apologise, he must go – and Tory MPs will be complicit until they force him out.”