The Prime Minister has not knowingly misled Parliament and the Conservatives are making “wild allegations” about the appointment of Peter Mandelson, Scottish Secretary Douglas Alexander has said.

He told GB News: “The fact is, the Prime Minister is being alleged by the Leader of the Opposition to have knowingly misled parliament and lied to the public. That is not true, and the Prime Minister will set out why that’s not true when he speaks at the dispatch box of the House of Commons just behind me this afternoon.

“But for that claim to be true would require you to set aside what’s a growing body of evidence that would suggest every minister involved in this decision to appoint Peter Mandelson, a growing number of senior civil servants, and indeed, the friends and ally of Olly Robbins, the former Under-Secretary at the Foreign Office, were all part of some grand conspiracy not to tell the truth. It’s simply not the case.

“The fact is, there was information in relation to deep vetting that was withheld both from the Foreign Secretary and from the Prime Minister, and he will account for that and explain that breakdown in process when he speaks to the House of Commons.”

He added: “The Conservatives are making wild allegations. That’s what opposition parties without much judgement in terms of when did the Prime Minister find out this information? As I say, there is a growing consensus, including Olly Robin’s allies and friends, the Cabinet Secretary, the Permanent Secretary in the Cabinet Office, and indeed the Prime Minister and all ministers involved, that the information was not shared by the Foreign, Commonwealth and Development Office, that the recommendation of the vetting agencies had not been followed.

“That’s now an established matter of fact, and yet we saw Kemi Badenoch as recently as Friday alleged that the Prime Minister had lied. That’s a very serious charge, and one that will be refuted, I believe, very effectively today.

“In terms of when did the Prime Minister find out the information, he was notified on Tuesday evening by the Permanent Secretary in the Cabinet Office, and the Cabinet Secretary present at that initial meeting on Tuesday evening was the Prime Minister’s Principal Private Secretary who took a minute, a note of that meeting.

“In that very meeting, the Prime Minister made clear that he wanted to return to Parliament to set the record clear in terms of what he knew and what he did not know, but that he required the facts in order to be able to do so. Why did he require the facts? Because the very central issue in dispute is whether facts were withheld from the Prime Minister.

“Your viewers would think it reasonable that he immediately commissioned those senior officials to get hold of all the facts, to equip them to be able to go back and answer questions in Parliament, and that’s exactly what he’ll do this afternoon at the dispatch box.

“I think it was perfectly reasonable for the Prime Minister on Tuesday evening, when made aware of this new information, to say, we need to get hold of all of the facts in relation to this, I can go to Parliament and set out the facts, because Parliament deserves the facts rather than simply allegations.

“One of the reasons that there is such concern over this controversy is that information was not only not provided to ministers, information therefore was withheld from Parliament. So it is right to obtain the facts in order to be able to inform Parliament of the facts. That is the responsibility of the Prime Minister, and that’s exactly what he’ll do this afternoon.”