The King (on the application of UCPI Designated Lawyer Officers Core Participant Group) v Sir John Mitting (Sitting as Chairman of the Undercover Policing Inquiry) (“UCPI”)

Hearing dates: 13 and 14 May 2026

Approved Judgment

This judgment was handed down remotely at 10.30am on 9 June 2026 by circulation to the parties or their representatives by e-mail and by release to the National Archives.

Lord Justice Singh and

Introduction

This is the judgment of the Court.

The principal issue in these judicial review proceedings is whether Sir John Mitting, sitting as Chairman of the Undercover Policing Inquiry (“UCPI”), whom we will hereinafter be referring to as the Defendant, has power under section 21 of the Inquiries Act 2005 (“the IA 2005”) to issue a notice on a former police officer, anonymised in the UCPI as HN86, compelling him to attend in London to give oral evidence, in circumstances where at the time the notice was served he was resident overseas. The second ground of challenge, which we consider to be very much subordinate to the first ground, is whether there was procedural unfairness in connection with the issue of the notice.

The UCPI was set up in 2015 following widespread and serious concerns about undercover policing operations over a number of decades. As specified in its Terms of Reference, the purpose of the UCPI is:

“… to inquire into and report on undercover police operations conducted by English and Welsh police forces since 1968 … [to include] … whether and to what purpose, extent and effect undercover police operations have targeted political and social justice campaigners … [and includes] the undercover operations of the Special Demonstration Squad.”

The Special Demonstration Squad (“SDS”) was an undercover unit operating within the Metropolitan Police Service (“MPS”), Special Branch, from c. 1968 to 2008. SDS undercover officers infiltrated and reported on groups assessed as capable of presenting threats connected with public disorder, extremism, subversion and terrorism. The SDS was managed by a Detective Inspector (“DI”) and Detective Chief Inspector (“DCI”) operating from an office in MPS premises.

HN86 served in the SDS as an undercover officer from the late 1970s (ceasing at some point in the 1980s), as a DI in 1990 (effectively as second-in-command of the SDS), and then as a DCI between 1991 and 1994 (effectively in command). He retired following a mental breakdown in the late 1990s. HN86 is now in his 70s and for approximately 25 years has lived overseas. HN86 retains his British nationality and has permanent residency in the country where he lives. He is in receipt of police and state pensions, pays tax on his police pension in the UK, and pays tax on his state pension and other income in his country of residence. He does not own property in the UK and returns only occasionally, most recently about three years ago for a wedding.

HN86 has the benefit of anonymity in the UCPI. No order to similar effect in these proceedings was made when permission to apply for judicial review was granted by Jay J on 6 March 2026, but we consider that the reasons justifying an anonymity order in the UCPI apply with equal force to the proceedings before us. It follows that we make such an order pursuant to CPR r. 39.2(4).

HN86 is not an Interested Party to these proceedings and he is not a Core Participant in the UCPI. A number of former MPS personnel, including HN86, are represented before the UCPI by the UCPI Designated Lawyer Officers Core Participant Group, hereinafter referred to as the Claimant. The Claimant's position is that it brings this claim for judicial review on behalf of the group it represents, including HN86. Save in relation to the Claimant's second ground of challenge, the Claimant's standing to bring this claim is not disputed by the Defendant.

The Defendant considers that HN86 is a witness of particular importance to the UCPI. The Claimant contends that the significance of HN86 as a witness has been overstated and invites us to refrain from making any findings as to the value or utility of his evidence to the Defendant. Given that no irrationality challenge to the section 21 notice has been brought and its merits are not in issue, we are content to accept the Claimant's invitation although we note the Defendant's case, as contained in paras 13–16 of his counsel's skeleton argument, setting out the three main reasons why HN86's oral evidence is now considered to be important. In particular, we record that the Defendant is of the view that there are a number of lines of inquiry to be pursued with HN86 in respect of which only he is in a position to assist. These include: oversight and authorisation of intelligence gathering on the Stephen Lawrence Campaign; allegations of racism and discriminatory targeting of campaigns; managerial knowledge (including knowledge of those senior to HN86) of undercover officers' sexual relationships; the use of identities of deceased children; and, undercover officer involvement in criminality. The Inquiry process would enable Counsel to the Inquiry to probe HN86's evidence, and core participants to put their own questions under rule 10 of the Inquiry Rules 2006 (2006 SI No. 1838) (“the Inquiry Rules”), either indirectly, through Inquiry counsel, or directly and with permission, by their own counsel.

The Claimant is represented by Oliver Sanders KC, Catherine Collins and Achas Burin. The Defendant is represented by Fiona Scolding KC, John Warrington, Sarah Hemingway, Julia Farrant and Charles Bishop. Baroness Doreen Lawrence, OBE, the Third Interested Party, is represented by Imran Khan KC. We are grateful to all the advocates for their written and oral submissions.

Essential Factual Background

In 2024 HN86 voluntarily agreed to receive a request under rule 9 of the Inquiry Rules for written evidence. He provided a partial response by way of statement dated 23 May 2024. To be fair to him, full compliance with the request would have been onerous.

On 1 August 2025 the Defendant gave a provisional indication to the Claimant through the Solicitor to the Inquiry that he would like HN86 to give oral evidence. On that date, and again on 4 September, the Claimant stated that it had not yet been able to make contact with HN86. On 24 September the Claimant was informed that the Defendant's view was that if HN86 was not willing to return to the jurisdiction but was prepared to give evidence remotely, that would be something that the Defendant would be happy to facilitate. On the same day the Claimant informed the Defendant that HN86 had now given his instructions, as follows:

“HN86 does not wish to give oral evidence, either in person or remotely. He remains unwell … I did specifically ask whether there were any circumstances in which HN86 would be prepared to give oral evidence, including remotely, but he said there were not.”

Again on 24 September, the Defendant stated that he required a medical report to be produced, and that the reporting doctor should be invited to consider whether there were any circumstances in which HN86 could give oral evidence, including before a private hearing with limited attendees. In response on the same day, the Claimant stated:

“We are not applying for HN86 to be excused on medical grounds. He is not agreeing to return to the jurisdiction to give oral evidence and has specifically stated that he does not want to give evidence either remotely or in private.”

Implicit in this response is the assertion that he could not be compelled by the Defendant to return to the UK.

On 29 September 2025 the Deputy Solicitor to the UCPI wrote to the Claimant setting out the matters we have just summarised as an explanation for the Defendant's reasons to serve a section 21 notice, as well as the possible consequences of non-compliance. The offer to HN86 to attend remotely was repeated. The notice itself included the following:

“ Notice to HN86 under section 21 of the Inquiries Act 2005

I have not received confirmation of your attendance to attend the Tranche 3, Phase 3 Evidential Hearings taking place at the International Dispute Resolution Centre to be held June — July 2026.

I require your in-person attendance at 9:30am on 13, 14 and 15 July 2026 at the International Dispute Resolution Centre, 1 Paternoster Square, London, EC4M 7BQ.

If you wish to make a claim that you are unable to comply with any part of this notice or that it is not reasonable in all the circumstances to require you to comply with this notice, as set out in Section 21(4) of the Inquiries Act 2005, you must notify the Inquiry in writing within twenty-one days of the date of this notice, giving reasons. I will determine any such claim and may vary or revoke this notice.

Possible consequences of non-compliance

1. You are liable to prosecution if you fail to...