I’ve long warned the Mandelson affair was descending into a cover-up

So where are the Mandelson/McSweeney emails? As The Mail on Sunday reports today, the Metropolitan Police and Downing Street are now engaged in a game of pass-the-parcel over what has happened to the politically explosive communications between Sir Keir Starmer’s former ambassador and his former chief of staff.

For months, I and other journalists have been warning that the Peter Mandelson scandal was descending into a cover-up. And that Starmer and his allies would do everything in their power to try to ensure the truth about the sorry saga did not come to light.

This morning we can see why. Because the Met and No 10 are now blaming each other for the failure to publish a crucial series of messages relating to the Cabinet reshuffle conducted on September 5, 2025, in the wake of Angela Rayner’s resignation.

Shortly after that enforced reorganisation of his government, rumours began to circulate that Starmer had not been alone in selecting new ministers. According to one ministerial source I spoke to at the time: ‘Peter Mandelson was in Downing Street. He was directing things. He was pulling the strings.’

At the time, that was furiously denied by No 10. Mandelson had been in the building on that day, they admitted, but had no role whatsoever in the reshuffle.

The issue was again probed last month when Morgan McSweeney – Starmer’s former chief of staff – appeared before the Foreign Affairs Select Committee.

The committee’s chairman, Emily Thornberry, questioned McSweeney about events on the day in question. He confirmed Mandelson had been present in the building, but insisted he had not met him. He further conceded the disgraced Labour peer had messaged him about the reshuffle, and that he had replied.

But McSweeney again insisted Mandelson had no role in any of the appointments. And, crucially, he told Thornberry the messages would all be released when the next tranche of Mandelson documents were published.

Keir Starmer talks with Britain’s then ambassador to the United States Peter Mandelson during a welcome reception at the ambassador’s residence on February 26, 2025 

The Met and No 10 are now blaming each other for the failure to publish a crucial series of messages relating to the Cabinet reshuffle conducted on September 5, 2025 (L-R: Angela Rayner, Shabana Mahmood, Keir Starmer, Peter Kyle, Hilary Benn, Rachel Reeves, Darren Jones and Thangam Debbonaire)

They were not. And the reason is now the subject of a row between the police and Downing Street officials. The Met insists it did not ask for a crucial series of messages to be withheld. Downing Street sources have briefed journalists that it did.

My understanding is there are at least two specific messages of particular importance that have been withheld. One is from Mandelson to McSweeney relating to the appointment of Darren Jones, who is Chief Secretary to the Prime Minister.

There was a debate inside No 10 about whether or not to significantly expand Jones’s role within government. According to a senior Cabinet minister: ‘Mandelson was directly involved in the discussions about what to do with Jones. He was taking a close interest in that.’

Jones’s relationship with Mandelson was dramatically thrown into the spotlight on Thursday, after a fawning message was published in which he heaped praise on the disgraced ambassador following his sacking, and expressed sympathy over his exit. This was despite the fact Jones had previously denied sending such a message.

The second significant piece of communication relates to a message from Mandelson to McSweeney about the Trade Secretary, Peter Kyle.

At the time, Kyle was science secretary and had been liaising closely with Mandelson on the development of numerous AI initiatives. According to a senior Cabinet minister: ‘Mandelson and Kyle were in regular contact. But Kyle was becoming frustrated. He felt he couldn’t push the AI agenda properly unless he was trade secretary.’

The reason why Mandelson’s communication to McSweeney in relation to Jones and Kyle is significant is because, as we know, both Downing Street and McSweeney have strenuously denied that Mandelson had any influence over the reshuffle.

In the event, Jones was indeed promoted in that reshuffle, being handed the dual briefs of Chief Secretary to the Prime Minister and Chancellor of the Duchy of Lancaster. Similarly, Kyle also received a major promotion, being moved from his science brief to the trade job he reportedly craved.

According to a senior Cabinet minister: ‘Mandelson and Kyle (pictured) were in regular contact. But Kyle was becoming frustrated. He felt he couldn’t push the AI agenda properly unless he was trade secretary’

There is an additional subtext to Mandelson’s interest in Kyle and the reshuffle.

In documents published last week, there are numerous references to the ongoing trade talks with the United States, and a series of complaints from Mandelson that details were being leaked from the Department of Trade.

But according to another senior Cabinet minister: ‘Those leaks were actually coming from Peter Mandelson himself. He was trying to undermine Jonathan Reynolds [the previous trade secretary] because he wanted his mate Kyle to be parachuted into the job.’

The major outstanding question, of course, is why any of this Westminster skulduggery has been hidden from public view. The Met denies it was responsible and is being tight-lipped about its investigation. The Met has said its inquiry is ongoing and has requested that any material is not published until it has had the opportunity to review it.

The initial probe, and formal arrest of Mandelson, followed reports he had passed on market-sensitive government information to his business associates, including the convicted paedophile Jeffrey Epstein.

It has also been reported that documents relating to Mandelson’s formal security vetting, and in particular his former and ongoing business relationships, have also been withheld at the Met’s request. As has a separate form he submitted relating to his declaration of business interests. There are other instructive gaps. Minutes of meetings held by Mandelson during his time as Washington ambassador have also not been released.

And then there is the ongoing mystery of ‘The Palantir Meeting’. In February 2025, shortly after seeing Donald Trump at the White House, Mandelson accompanied the Prime Minister to a meeting at the Washington DC headquarters of the technology giant.

Contrary to Cabinet Office rules, it was not included on his formal schedule, and no minutes of the meeting were taken.

Downing Street later attempted to claim the meeting had not been a meeting at all, even though Starmer subsequently admitted it was in the House of Commons, and this was later confirmed by the Ministry of Defence.

Palantir was a major client of Mandelson’s consulting firm Global Counsel. According to a Cabinet minister I spoke to, a week after Starmer returned they and some colleagues received a message from Downing Street. ‘It told us we had to sit down with representatives of Palantir to see what they could do for us,’ the minister revealed.

Mandelson strenuously denies any wrongdoing. As does No 10. But in the case of Downing Street, we have heard these denials before.

We heard them when the mobile phones started to be stolen. We heard them when the messages started to vanish. And we heard them when documents started to disappear into the electronic ether.

So if the police did not order the Mandelson/McSweeney emails be withheld, then who did, and why?

When we have the answer to that, we will be a lot closer to finally getting to the truth of the Mandelson affair. A truth Keir Starmer and his allies are doing everything in their power to hide from the British people.