Sir Keir Starmer has ruled out any future government role for Peter Mandelson, weeks after sacking him over his relationship with the paedophile financier Jeffrey Epstein.
The prime minister fired the Labour peer after the publication of emails that showed Lord Mandelson sent supportive messages to Epstein even as the latter was facing jail for sex offences.
No 10 said the emails revealed “materially different” information from what was known when Lord Mandelson was appointed to the key role of UK ambassador to the US earlier this year.
The Labour grandee left the government less than a week after Sir Keir lost his deputy prime minister Angela Rayner, who resigned over her failure to pay enough tax on her new home.
Last week Sir Keir suggested that she could return to government, and predicted that she would remain a “major voice” in British politics for years to come. But he made clear that there was no route back for Lord Mandelson.
The prime minister was asked by journalists travelling with him on a two-day trade mission to India whether he could see a future in frontline politics for Lord Mandelson, and whether he would let him have the Labour whip in the Lords.
He replied: “Not in a government role, in terms of future appointments.”
He added: “And I think Peter is also on a leave of absence from the Lords in any event, so the issue of the whip doesn’t arise.”
Sir Keir sacked Lord Mandelson a day after telling the Commons he had “confidence” in his ambassador, a situation even Labour MPs described as “embarrassing”.

It followed the publication of a series of emails that showed Lord Mandelson had sent supportive messages even as Epstein faced jail for sex offences.
No 10 and the Foreign Office said the emails showed that “the depth and extent” of Lord Mandelson’s relationship with Epstein was “materially different from that known at the time of his appointment”.
The emails included passages in which Lord Mandelson told Epstein to “fight for early release” shortly before he was sentenced to 18 months in prison.
He is also reported to have told Epstein “I think the world of you” the day before the disgraced financier began his sentence for soliciting prostitution from a minor in June 2008.
Sir Keir was accused by the Tories of an “extraordinary error of judgement” in appointing the peer to the crucial role, which forms a key link between the UK and Donald Trump’s White House, as the fact that Lord Mandelson had had a longstanding relationship with Epstein was already well known.
His sacking came a day after the then ambassador said he was “very embarrassed” to read a birthday message he’d written to Epstein in which he had described him as his “best pal”.
The message, part of a 50th birthday book compiled for Epstein by his partner Ghislaine Maxwell, who is now in prison after being convicted of sex trafficking, also saw Lord Mandelson express “love” for the financier and joke about entertaining his “interesting” friends.

Last week Sir Keir hinted that Ms Rayner could return to government, just weeks after she resigned from the cabinet.
The prime minister hailed Ms Rayner as a “great story for social mobility”, and said he believes she will be a “major voice” in British politics for years to come.
The health secretary Wes Streeting also told Labour’s annual party conference that the government “needs” her back, following her work on the Employment Rights Bill.
Sir Keir said: “I was personally very sad to see her go. If you talk about social mobility, there is no greater story than Angela Rayner coming from very difficult circumstances to become deputy prime minister.”
He added: “She’s paid a heavy price indeed, and I’ve always thought that she will be a major voice again in the Labour movement, and I think that is a good thing.
“I’ve been really struck, since she did step down, by the number of people from different political walks of life who say to me they do want to see Angela Rayner have that voice again at some stage.”