The UN Working Group on Arbitrary Detention has found the post-tariff IPP detention of five prisoners in England and Wales to be arbitrary under international law, upholding all three grounds advanced on their behalf in Opinion No. 16/2026. Their lawyers are now preparing a habeas corpus challenge to the High Court, a rare procedural step that would require the government to justify the men’s continued detention before senior judges.
What did the UN Working Group find about IPP detention?
In its first published opinion on imprisonment for public protection, the Working Group concluded that there was no legal basis in international law for the five prisoners’ continued detention beyond their tariffs, that the government had not established compelling reasons why the risk each man poses could not be managed by alternative measures, and that the parole system fails to provide an effective mechanism for challenging the lawfulness of continued detention. The five men have served a combined total of almost 87 years in custody on their IPP sentences. One of them, Josh McRae, died in custody in 2025 at the age of 34. The Working Group also found that holding one prisoner, clinically assessed as requiring psychiatric hospital treatment, in ordinary closed prison segregation rather than transferring him to an appropriate facility constituted discrimination on the grounds of disability, and it said the men are entitled to compensation.
Is a UN Working Group opinion binding on the UK?
No. The Working Group is a body of independent experts reporting to the UN Human Rights Council, and its opinions carry persuasive rather than binding force in domestic law. Their practical weight lies elsewhere. An adverse opinion from the UN’s principal mechanism on unlawful detention arms the forthcoming domestic litigation, sharpens political pressure for a resentencing exercise, and puts the United Kingdom in the uncomfortable position of being told by the body it routinely cites against other states that it is holding prisoners arbitrarily. The government has faced that dynamic before, notably over the Assange finding, and has resisted it, though rarely on an issue where domestic parliamentary committees have already reached similar conclusions about the sentence itself.
What is the habeas corpus challenge now in preparation?
Alun Jones KC and Dr Muin Boase of Great James Street Chambers, who represented the five men before the Working Group, are preparing an application for the writ of habeas corpus to the High Court. Habeas corpus tests the legality of detention itself rather than the process that produced it, which distinguishes the application from a conventional judicial review of a Parole Board decision and explains why the route is so rarely used against sentences imposed by a court. The application will confront settled domestic authority that a lawfully imposed indeterminate sentence founds lawful detention until the Parole Board directs release, and its prospects will turn on whether the Divisional Court can be persuaded that the international law findings bear on that analysis. Whatever the outcome, the government will be forced to defend the continued imprisonment of over-tariff IPP prisoners in open court, on evidence, for the first time since abolition.
Where does this leave IPP reform?
Around 8,000 IPP sentences were imposed between 2005 and 2012, and although the sentence was abolished in 2012 the change was not retrospective, leaving 2,271 people still in prison on the latest published data, many of them years or decades over tariff. The Sentencing Act 2026 did not resolve their position, as we reported when the Act’s release changes were paused, and the new progression model tracked in our Sentencing Act progression tracker excludes them. The politics may now be shifting. The prime minister, Andy Burnham, said this week that he intends to resolve what he called a long-running injustice, with the release of lower-risk IPP prisoners among the options under consideration as part of measures to ease prison overcrowding, a position he had begun to signal in remarks noted in our early August roundup.
An adverse UNWGAD opinion is not binding, but it converts a long-standing campaigning position into a reasoned international ruling, and it lands just as a habeas corpus application heads for the High Court and a prime minister signals willingness to act. For practitioners with IPP clients, the opinion supplies fresh material for parole representations and for challenges to segregation and hospital-transfer decisions, and the compensation finding opens a further front entirely.
The opinion is published on the OHCHR website, and the statutory sentence it concerns was created by section 225 of the Criminal Justice Act 2003.