During Prime Minister’s Questions on Wednesday, Tory leader Kemi Badenoch accused Sir Keir of knowing about his former spin-doctor’s association with Moray councillor Morton when Lord Doyle took his seat.

The Labour leader replied: “Matthew Doyle did not give a full account of his actions. On Monday, I promised my party and my country there will be change. And yesterday, I removed the whip from Matthew Doyle.”

Previously, Sir Keir has insisted Lord Mandelson did not tell him the full truth about his friendship woth sex offender Jeffrey Epstein.

A Conservative Party spokesman said: “The Prime Minister is once again trying to duck and cover – but his flimsy excuses simply won’t wash.

“There was an investigation into Matthew Doyle by his new chief of staff. There was reporting on the front of The Sunday Times. How on earth is Keir Starmer once again trying to claim ignorance?

“Kemi Badenoch wrote to Starmer last week demanding the release of the advice he received before making another associate of a paedophile a peer.

“We must know what he knew and when. It’s time to publish the papers in full, including details of the Downing Street investigation and his correspondence with the House of Lords Appointments Commission. No more cover-ups.”

Lord Doyle campaigned for Morton in 2017 after the candidate had been charged over indecent images of children, saying he believed his assertions of innocence. The councillor later admitted having the images.

In a statement, Lord Doyle apologised “unreservedly” for supporting Morton before the case against him had concluded.

He said he also had “extremely limited” contact with Morton after his conviction.

He said: “I want to apologise for my past association with Sean Morton.

“His offences were vile, and I completely condemn the actions for which he was rightly convicted. My thoughts are with the victims and all those impacted by these crimes.

“At the point of my campaigning support, Morton repeatedly asserted to all those who knew him his innocence, including initially in court. He later changed his plea in court to guilty.

“To have not ceased support ahead of a judicial conclusion was a clear error of judgment for which I apologise unreservedly.”

The Scottish National Party had objected to Lord Doyle’s peerage, and Mrs Badenoch called on Sir Keir to publish “vetting advice and due diligence” reports provided before his appointment to the Lords.

Lord Doyle took his place in the upper chamber in January.

Labour had suspended Morton after he appeared in court in connection with indecent child images in late 2016.

Lord Doyle campaigned for Morton when he ran as an independent in May 2017.

Morton admitted having indecent images of children in November 2017.

Lord Doyle said: “Those of us who took him at his word were clearly mistaken. I have never sought to dismiss or diminish the seriousness of the offences for which he was rightly convicted.

“They are clearly abhorrent and I have never questioned his conviction.

“Following his conviction any contact was extremely limited and I have not seen or spoken to him in years.

“Twice I was at events organised by other people, which he attended, and once I saw him to check on his welfare after concerns were raised through others.

“I acted to try to ensure the welfare of a troubled individual whilst fully condemning the crimes for which he has been convicted and being clear that my thoughts are with the victims of his crimes. I am sorry about the mistakes I have made. I will not be taking the Labour whip.

“For the avoidance of any doubt, let me conclude where I started. Morton’s crimes were vile and my only concerns are for his victims.”

Labour said the whip had been withdrawn from Lord Doyle while an investigation is carried out.

A Labour spokesman said: “All complaints are assessed thoroughly in line with our rules and procedures.”

Mrs Badenoch said: “Keir Starmer handed a peerage to Matthew Doyle despite knowing about his ongoing friendship with a man charged with child sex crimes.

“The Prime Minister has now suspended the whip, but he must come clean about what he was told before making this appointment. We won’t let this go.”