The scandal erupting in relation to the latest revelations about Peter Mandelson’s  relationship with the multi-millionaire convicted child sex offender Jeffrey Epstein, who died in prison awaiting trial for a litany of further sex trafficking offences, has become one of the biggest in modern British political history.  Having been sacked from his post as US Ambassador in September 2025, Mandelson has now resigned from the House of Lords, legislation to allow him to be stripped of his life peerage is likely to follow, and he is being investigated for the criminal offence of misconduct in public office.

It seems abundantly clear that Mandelson, when in post as a government minister (indeed ‘de facto deputy Prime Minister’) violated confidentiality rules in 2009 by sharing market sensitive government emails directly with Epstein.  This included forwarding official advice concerning the UK government’s economic plan during the financial crisis, revealing the terms of an imminent European bailout, and even the fact that Mandelson had persuaded the then Prime Minister Gordon Brown to step down following the 2010 general election.

Of course, these egregious actions (among others dubious connections with Epstein which have now been exposed, including Mandelson’s apparent receipt of significant payments while an MP in 2003-4) are not Mandelson’s first encounter with scandal.  The man known as ‘the prince of darkness’ is among the elite group of government ministers who have been forced to resign from government not just once, but twice, following controversial conduct earlier in his career.  In 1998 Mandelson resigned following the revelations he had been granted a secret interest-free loan from a ministerial colleague, Geoffrey Robinson, whose business affairs Mandelson’s department was investigating.  After returning to government, Mandelson was then forced to resign again in 2001 following allegations that he had intervened to help a wealthy donor to the Millenium Dome project to secure a British passport.

The fact that Mandelson also violated confidentiality rules when returning to government after these first two scandals seems beyond doubt in light of the emails released in the US by the Department of Justice under the Epstein Files Transparency Act 2025.  The Ministerial Code in the UK is clear that ‘the principle of collective responsibility applies to all ministers’ [para 1.6(b), 2025] and the idea of collective responsibility includes obligations as to the confidentiality of government communications (see eg Marshall, Constitutional Conventions (1987)).  Where ministers have shared confidential information in recent years, they have been removed from their positions in government, as occurred with Gavin Williamson in 2019 and Suella Braverman in 2022 (albeit in Braverman’s case for a mere six days before she was restored to government when Rishi Sunak replaced Liz Truss as Prime Minister).  While Mandelson’s breach of these rules has come to light many years after it occurred – and even then, not as a result of any domestic accountability processes, but as an indirect consequence of the ongoing American investigations into Epstein – there are still potential criminal consequences for him to face, in addition to the loss of his title and (presumably this time) the absolute conclusion of his political career in disgrace.

Yet given the relative clarity which now exists concerning Mandelson’s position, the more pressing constitutional questions concern the position of the current Prime Minister, Keir Starmer.  After all, it was Starmer who allowed Mandelson to revive his political career for the umpteenth time, by appointing him to the highly prestigious post of US Ambassador in February 2025.  Even aside from Mandelson’s deeply contentious previous history, the appointment of such a political figure to this post was itself a controversial move.  And as noted above, this appointment had already ended in scandal – Mandelson was sacked as Ambassador by Starmer months after his appointment following an earlier public disclosure of emails which showed he remained in close contact with Epstein even after his conviction as a sex offender and subsequent release from prison. 

The new revelations about Mandelson’s disclosures to Epstein, and the Prime Minister’s response to them, raise further questions about Starmer’s own conduct in relation to the Ministerial Code.  The Prime Minister has now confirmed in the House of Commons on 4 February 2026 that he knew that there had been an ongoing friendship between Mandelson and Epstein when appointing him as US Ambassador.  The Leader of the Opposition, Kemi Badenoch, asked the Prime Minister: ‘did the official security vetting he received mention Mandelson’s ongoing relationship with the paedophile Jeffrey Epstein?’  And Starmer eventually confirmed that ‘yes, it did. As a result, various questions were put to him’.  The government has agreed that documents related to the vetting process will be released – some following security vetting by the Intelligence and Security Committee of Parliament – although there is also pressure from the Metropolitan Police for the government not to release any information which could undermine the newly commenced criminal investigation or prejudice a future trial. 

The release of these documents is important to the Prime Minister as he hopes that it will vindicate his defence of the appointment of Mandelson, which is that he lied during the appointment process: ‘I want to make sure this house sees the full documentation, so it will see for itself the extent to which, time and time again, Mandelson completely misrepresented the extent of his relationship with Epstein, and lied throughout the process, including in response to the due diligence.’

The disclosure of these documents will be important to try to understand the seriousness of the vetting process to which an unconventional appointment like Mandelson was subjected.  Yet the questions for the Prime Minister should not end there – instead, there are major questions about whether the Prime Minister has violated the Ministerial Code by appointing Mandelson when in possession of information demonstrating that he had a relationship of any kind or extent with a man such as Epstein.

The Ministerial Code is of course an imperfect document.  It is written by and issued under the authority of the Prime Minister himself.  It purports to establish the standards expected of other government ministers by the Prime Minister, who is the ultimate arbiter of the rules and principles contained within it.  The status of the Code, and the Prime Minister’s ownership of it, make the application of these rules to the Prime Minister themselves a potential anomaly.  The Code is explicit that ‘[t]he Code is the Prime Minister’s document. As such, the Prime Minister is the ultimate judge of the standards of behaviour expected of a minister and the appropriate consequences of a breach of those standards’ [para 2.3].  This formulation might suggest the Prime Minister sits above the obligations contained in the Code – that these are rules for other ministers, not for him.  Yet at the same time, the ‘General Principles’ of the Code are expressed as applying to all ‘Ministers’, of which of course the Prime Minister is one:  for example, ‘Ministers are expected to maintain high standards of behaviour and to behave in a way that upholds the highest standards of propriety’ [para 1.1]. 

The applicability of the rules in the Code to the Prime Minister has been an issue in the past, particularly in the government of Boris Johnson.  The previous Independent Adviser on Ministers’ Interests, Lord Geidt, was asked in December 2021 to evaluate Johnson’s conduct by reference to the terms of the Ministerial Code in relation to the ‘wallpapergate’ scandal (in relation to which he cleared Johnson of breaching the Code).  Geidt also criticised Johnson in 2022 for failing to explain his conduct in relation to the Covid-19 ‘partygate’ scandal, by making no ‘public reference to your own conduct under the Ministerial Code’.  Geidt then resigned on the basis that he was being asked to sanction breaches of the Ministerial Code, and in response told the Prime Minister that ‘you and any other Minister should justify your position vis-à-vis the Code in such circumstances’.  Taken together, this strongly suggests the Prime Minister’s conduct is susceptible to investigation where a breach of the Code is suspected.

There is no sign yet that Starmer is about to self-refer his conduct in relation to the appointment of Mandelson as US Ambassador for investigation under the Code.  Yet following reforms which strengthened the powers of the (now renamed) Independent Adviser on Ministerial Standards, introduced by Starmer in 2024, self-referral is no longer required, and nor does the Prime Minister retain a veto over whether an investigation can proceed.  Instead, the Adviser has the power to launch an investigation on their own initiative under para 2.6(b) of the Code: ‘[w]here the Independent Adviser believes that an alleged breach of the Code warrants further investigation and that matter has not already been referred to them, they may initiate an investigation after notifying the Prime Minister. Ministers are expected to provide the Independent Adviser with all information reasonably necessary for the discharge of their role.’ 

The removal of any veto on the power of the Adviser to launch an investigation under the Code has been promoted by the current government as an important strengthening of the UK’s political standards system.  The power does not appear to have been used to this point, and the Mandelson scandal could now prove a real test of its utility.  How an ‘alleged breach’ of the Code could be communicated to the Adviser is unclear, given there is no public complaints system.  Yet it does appear there is at least a prima facie case to investigate here, and the failure of the Adviser to consider these issues would reveal a major weakness in the current system.

On what basis can the Prime Minister be said to have breached the Code?  Its terms are of course broad and open to interpretation – yet reading the general principles it is not difficult to see a potential issue in light of Starmer’s confirmation of his awareness of Mandelson’s compromising relationship with Epstein at the moment of appointment (even if the emails indicating breaches of confidentiality rules were not available at that time).  Can the appointment of Mandelson in such circumstances be said to satisfy the principle that Ministers are expected to ‘behave in a way which upholds the highest standards of propriety’?  Can that decision be reconciled with the aspiration that ‘Ministers should recognise that as office-holders, they are held to the highest possible standards of proper conduct, and ensure that they are living up to those standards in their words and actions’?  When Starmer has – in the foreword to the Ministerial Code and elsewhere – extolled the virtues of ‘restoring politics to public service’ through adherence to high standards, and described the Code itself as ‘not just rules and principles, but a statement of values’, the gravity of these words should be clear. 

And there is further recent evidence that the broad principles in the Code should not be simply seen as hot air, to be discarded when it is the Prime Minister’s own conduct, judgement and decision-making under scrutiny.  The idea that government ministers should be expected to meet the ‘highest possible standards of proper conduct’ was central to the current Independent Adviser’s determination in September 2025 that the former deputy Prime Minister, Angela Rayner, had violated the Code.  It was this broad principle which the Adviser decided had ultimately been breached, rather than any more specific rule or provision of the Ministerial Code.  As Sir Laurie Magnus noted in concluding his letter to the Prime Minister:

 I believe Ms Rayner has acted with integrity and with a dedicated and exemplary commitment to public service. I consider, however, that her unfortunate failure to settle her [stamp duty land tax] liability at the correct level, coupled with the fact that this was established only following intensive public scrutiny, leads me to advise you that, in relation to this matter, she cannot be considered to have met the “highest possible standards of proper conduct” as envisaged by the Code. Accordingly, it is with deep regret that I must advise you that in these circumstances, I consider the Code to have been breached.

In light of this conclusion, Rayner resigned.

The Independent Adviser therefore faces a decision.  There is at least a plausible argument that the Prime Minister’s conduct in appointing Mandelson, while aware that he had a continuing relationship of any kind with Epstein, does not meet ‘the highest possible standards of proper conduct’.  If the Prime Minister does not refer himself for investigation under the Code, the Adviser has the power to initiate such an investigation himself.  While the Code is in many ways a limited tool of political accountability, especially when applied to the Prime Minister themselves, there is a clear mechanism by which it could be invoked here.  And although it is the politics of this scandal which are likely to determine the Prime Minister’s future, the very fact of an investigation into this decision by reference to the Code, whatever the outcome, would in itself damage the government and contribute to that wider hostile political climate.  Whether the post of Ministerial Standards Adviser is really sufficiently ‘Independent’ of the government and the Prime Minister to take such a step will be a fundamental test of the current arrangements for evaluating the conduct of ministers, at a time when ethical standards in UK public life appear to have reached another new low.

Mike Gordon, Professor of Constitutional Law, University of Liverpool

(Suggested citation: M. Gordon, ‘Mike Gordon: The Mandelson Scandal and the Prime Minister: Investigating a Breach of the Ministerial Code’, U.K. Const. L. Blog (5th February 2026) (available at https://ukconstitutionallaw.org/))