Keir Starmer has accused his opponents of making politically motivated allegations about the Mandelson vetting scandal.
It comes after the British Prime Minister said he had been exonerated over accusations he misled MPs by evidence from Olly Robbins – the former British foreign office chief he sacked last week.
Starmer was asked whether he had considered resigning during a visit to Newcastle on Thursday.
He said: “Last week, my political opponents were saying that there’s no way a civil servant wouldn’t have told me about the outcome of a developed vetting security exercise.
“Turns out my political opponents were completely wrong about that.
“Then they said that I was dishonest.
“It turns out they were completely wrong about that.
“They are now putting any allegation they can and I will tell you for why – they are opposed politically to what this Government is trying to achieve.”
Conservative leader Kemi Badenoch is said to be pressing for his referral to the Privileges Committee claiming he misled MPs, The Times reported.
The same committee found former British prime minister Boris Johnson lied to the Commons over so-called partygate.
The Tory leader has suggested Starmer misled the Commons when he said “due process” had been followed in the appointment of Lord Mandelson as British ambassador to the US, according to the newspaper.
Amid reports of a split behind the scenes, the Prime Minister said his Cabinet was “working really hard” to counter the impact on the UK of the wars in Ukraine and Iran.
Starmer also repeated that he thought Robbins was wrong not to have told him the outcome of the so-called developed vetting process and insisted that as prime minister he could have been passed the top secret information.
“I strongly think that the outcome of the security clearance exercise, the developed vetting exercise, was important and should have been brought to my attention, and could have been brought to my attention, and had it been brought to my attention before Peter Mandelson took up his post, I wouldn’t have appointed him,” he said.
Senior civil servant Cat Little earlier told MPs due process was followed in the vetting process.
The British Cabinet Office permanent secretary has been uncovering documents related to the peer’s appointment to the role being released under the humble address process forced by MPs in February.
She answered questions at the Foreign Affairs Committee after Robbins appeared before the same group of MPs earlier this week.
Little said: “So my view is that due process was followed, and if I might explain why I believe that, it is because the process as I’ve outlined to the committee is that UKSV (UK Security Vetting) make a recommendation and the Foreign Office make a decision as to whether to grant DV (developed vetting).
“That is the process, and that is the process that is agreed with the Foreign Office.”
Little found out on March 25th that Mandelson had been granted high-level security clearance despite vetting officials recommending against it.
But she did not tell the British Prime Minister until several weeks later on April 14th, as she first sought expert legal advice about how to deal with such sensitive information.
Little said Robbins had refused to share vetting information with her and that she then took the “very unusual” decision to request it from security officials directly.
“I felt that I needed to see some relevant documentation so that I could advise the Prime Minister as to whether we had fully complied and gathered the information that was available and within scope,” she said.
Meanwhile, Labour backbenchers have openly voiced doubts about Starmer’s future since it emerged last week the British Foreign Office decided to appoint Mandelson despite the fact he failed the vetting process.
However, junior minister Alex Norris on Thursday said claims of a Cabinet split over the scandal are “a load of guff” and insisted Starmer would lead Labour into the next election.
On Wednesday, Work and Pensions Secretary Pat McFadden repeatedly declined to say whether he believed the sacking of Robbins was fair.
Starmer’s former chief of staff Morgan McSweeney has also been summoned to appear before the Foreign Affairs Committee next week.
The British Prime Minister is under further pressure ahead of May’s elections for English councils and the Scottish and Welsh parliaments.
YouGov projections indicated Labour was on course for disastrous results in its former London and Welsh strongholds.