Great James Street Chambers is delighted to congratulate Muin Boase and Alun Jones KC, following the publication of Opinion No. 16/2026 by the United Nations Working Group on Arbitrary Detention, in which they successfully represented five IPP prisoners in a landmark international human rights challenge against the United Kingdom.

The UN Working Group upheld all three grounds advanced by Dr Boase and Alun Jones KC, finding that the continued detention of the five prisoners amounted to arbitrary detention under international law.

https://www.ohchr.org/sites/default/files/documents/issues/detention-wg/opinions/session105/a-hrc-wgad-2026-16-united-kingdom-great-britain.pdf

The Opinion concludes that:

• There was no legal basis in international law for the prisoners’ continued post-tariff detention.
• The current parole system failed to provide an effective mechanism for challenging the lawfulness of continued detention.
• In the case of one petitioner, the suspension of parole reviews during psychiatric hospitalisation amounted to discrimination based on disability.

This significant decision represents one of the first occasions an international body has found post-conviction preventative detention of this nature to be arbitrary. The Working Group also called upon the UK Government to take the necessary steps to remedy the violations identified and to undertake a full and independent investigation.

The case was led by Muin Boase and Alun Jones KC, supported by Dean Kingham, Alison Gurden (Great James Street Chambers), the Public International Law Consultancy, Mariana Drinkwater, IPP Committee in Action, IPP Solidarity Movement, and the International Human Rights Clinic at the University of Derby.

Congratulations to Muin and Alun on securing this important decision, which represents a significant development in the field of international human rights law and the ongoing legal scrutiny of IPP sentences.

Muin Boase and Alun Jones KC are now considering the next steps following the Working Group’s Opinion. Those wishing to make enquiries regarding this matter, including potential claims or media enquiries, are invited to contact the clerking team at clerks@greatjames.co.uk.