Blog: Will publication of Arcuri diaries change the game on PM misconduct?

9 Dec 2021

As news reports claim that Jennifer Arcuri will provide new evidence of wrongdoing by Boris Johnson, civil litigation partner Stefano Ruis and paralegal Aleister Adamson assess the likelihood – and shape of – any potential criminal investigation into the Prime Minister.


The question of whether the Prime Minister Boris Johnson should face censure for his involvement with US businesswoman Jennifer Arcuri has recently garnered increased media attention.

The allegations against Mr Johnson are that while serving as Mayor of London between 2012 and 2016, he failed to disclose his interests in Ms Arcuri’s companies and to have influenced decisions relating to the payment of public money to those companies.

According to recent news reports Ms Arcuri has now agreed to allow the publication of selected extracts from her personal diary which she says support her claim that Mr Johnson offered to be a ‘throttle’ which would accelerate her fledgling tech business career. These diary extracts are also said to address the allegation that Mr Johnson acted against the advice of his staff by attending a promotional event in April 2013 for Ms Arcuri’s company Innotech.

The question is whether, five years on from the pair’s alleged affair, the promised publication of these diaries exposes the now Prime Minister to a greater risk of criminal investigation – and even prosecution.

IOPC decision not to investigate

In 2020 the IOPC announced that it would not pursue a criminal investigation against Mr Johnson. It concluded that while a romantic relationship may have existed between Mr Johnson and Ms Arcuri, the evidence available to it did not indicate the then Mayor of London influenced the payment of tens of thousands of pounds in public funds as sponsorship money and grants to Arcuri’s businesses.

The IOPC left it to the Greater London Authority (GLA) to decide whether Mr Johnson’s failure to register his interest with Ms Arcuri breached its Code of Conduct.

At the time of writing the GLA has not yet ruled on this. But Ms Arcuri’s diary entries, which she has agreed to share with the GLA, raised possibility of the authority referring the whole issue back to the IOPC which could, in turn, trigger a criminal investigation into misconduct in public office.

Misconduct in public office

The criminal offence of misconduct in public office is committed where (i) a public officer acting as such (ii) wilfully neglects to perform his duty and/or wilfully misconducts himself (iii) to such a degree as to amount to an abuse of the public’s trust in the office holder, and (iv) does so without reasonable excuse or justification.

The question of whether Mr Johnson wilfully misconducted himself could turn on the content of these diary entries. The IOPC previously found no evidence that Mr Johnson influenced sponsorship payments to Ms Arcuri’s businesses, despite their finding that evidence suggested that those officers making decisions about the award of funds were influenced by the close relationship between Mr Johnson and Ms Arcuri. A released diary entry has already suggested that Mr Johnson acted against advice by attending the 2013 Innotech event. If further entries suggest that Mr Johnson actively sought to influence sponsorship decision-making, this could suggest wilful misconduct. Any prosecution would be contingent on this conduct being deemed by the courts as harmful to the public interest and deserving of punishment.

Misfeasance in public office

Might other legal remedies exist for improper conduct by public officials? The tort of misfeasance in public office reflects the recognition in common law that public powers must be used in pursuit of the public good, and not for improper purposes.

The ingredients of the tort are that the defendant (i) must be a public officer; (ii) who exercised power as such; (iii) with malice or in bad faith; (iv) intending to injure the claimant or without an honest belief that his conduct was lawful. Malice or bad faith in this sense, can be “targeted” (intent to cause injury to identified persons) or “untargeted” (acting unlawfully in the knowledge of or being reckless as to the risk that the act will probably injure a person or persons). To succeed however, a claimant must also show that they have suffered foreseeable material injury or damage as a consequence.

Whilst the Prime Minister is clearly a public officer, and notwithstanding that there may be some scope for debate as to possible malice or bad faith (as was the case in the original IOPC investigation), the lack of any identifiable claimant inevitably precludes an action for misfeasance in this debacle. Without actual damage or loss moreover, there can be no cause of action in civil law even if a particularly egregious abuse of power could be shown. Arguably, whilst the payment of public funds by way of sponsorship money to Ms Arcuri may amount to the necessary loss it would likely be considered too remote for an individual claimant to succeed in any civil claim.


It is clearly in the public interest that credible allegations of misconduct perpetrated by Boris Johnson should be investigated as thoroughly as possible. The allegations against the Prime Minister are serious.

But the question of credibility has not yet been resolved. We simply do not know whether the new diary evidence is sufficiently strong to request the IOPC reopen its investigation. Any future criminal investigation or prosecution will rely, to a great extent, on the evidential weight of the diaries themselves. It would be a mistake to attempt to determine this before they have been released.



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