Minister Liam Byrne's WhatsApp messages missing from Mandelson files

The chats were expected to appear in the batch of Mandelson files, published earlier this week following MPs' vote to disclose documents relating to the disgraced peer's appointment as UK ambassador to the US.

Conversations between Jones and Lord Mandelson did not appear in the 1,500 pages of documents published on Monday, but some messages have been published in the Spectator.

On the day Sir Keir Starmer dismissed Lord Mandelson from his ambassadorial role, Jones wrote: "You've been doing such a great job, and you worked wonders with Trump. I'm so sorry about today."

In another exchange about Reynolds' special advisers and industrial policy advisers, Jones said: "I lost faith in his spads when, on a call about Port Talbot, they repeatedly took a different position to us in HMT [the Treasury] 'because that's what the unions want'."

Talking about his ambitions, Jones said his first preference was a role in the Department for Business and Trade, then headed by Reynolds but now led by Peter Kyle.

That was followed by the Department of Science, Innovation and Technology, then led by Kyle and now by Liz Kendall, or the Department for Energy Security and Net Zero, led by Ed Miliband both before and after the reshuffle.

Jones told Lord Mandelson that was because he thought defence secretary John Healey was doing a good job but suggested Reynolds may not be, saying: "DBT my preference – everyone fond of Jonny but perception that DBT not firing on full cylinders…"

Responding to an earlier debate on the Mandelson files in the House of Commons on Wednesday, Jones told MPs he had turned on the disappearing messages feature in WhatsApp, which is allowed under current ministerial guidance.

He said: "Moving to the documents that Members may have expected to see in the second tranche, as I said on Monday, some messages may not have been captured where people may have previously changed their phones without having backed up their messages or where they had disappearing messages turned on, and I noted to the House on Monday that that included myself.

"In my circumstance, to answer the questions from the shadow Chancellor of the Duchy of Lancaster [Alex Burghart], it is not that I took a unilateral decision about messages that I felt were in scope or not in scope of the Humble Address; it is merely that I have access to no messages to disclose."

He said he had not consciously ignored negative stories about Lord Mandelson and denied having been given any warnings about the Labour veteran.

"I think the answer to that question is yes, I did. Have I benefited from that relationship in the time I have been an elected politician? I think in part the answer to that question is yes, I did.