Judicial Review – Equality Act Disability Exclusion, Detention Powers and Forum in Immigration Discrimination Claims

R (on the application of MM) v Secretary of State for the Home Department [2026] EWHC 448 (Admin)

Matthew Howarth and Jack Holborn (39 Essex), instructed by the Government Legal Department, appeared on behalf of the Secretary of State for the Home Department
before Paul Bowen KC, sitting as a Deputy Judge of the High Court, in this significant Administrative Court matter. Shu Shin Luh of Doughty Street Chambers acts for the Claimant.

In an important preliminary ruling, the court granted the Secretary of State permission to amend her defence to raise two substantial new arguments, while confirming that the claim should remain in the Administrative Court for determination at the resumed substantive hearing.

The case is a key one in this developing area of public and immigration law. The resumed hearing will determine important unresolved questions concerning the scope of paragraph 16 of Schedule 3 to the Equality Act 2010 in the immigration context, the proper forum for Equality Act damages claims brought alongside judicial review grounds, and the effect of section 44 of the Border Security, Asylum and Immigration Act 2025 on the lawfulness of earlier immigration detention.

Matthew Howarth has previously appeared as sole counsel for the Secretary of State in earlier successful hearings in the same litigation, including MM, R (On the Application
Of) v Secretary of State for the Home Department & Anor [2025] EWHC 143 (Admin) and R (MM) v SSHD [2024] EWHC 1577 (Admin). The matter is now set down for a further hearing in June.

Case Background

The Claimant, MM, is a national of Niger who arrived in the United Kingdom in or about August 2021 and claimed asylum shortly thereafter. Following convictions at Lincoln
Crown Court for arson and assault by beating, for which he received a sentence of six months’ imprisonment, the Secretary of State served a Stage 1 Liability to Deport Notice on 2 October 2023 under section 3(5)(a) of the Immigration Act 1971, and MM was subsequently detained under Schedule 3 to the 1971 Act.

MM alleges that he suffers from significant mental impairment and challenges both the deportation decision and the lawfulness of his subsequent detention. He was released
from immigration detention on 12 May 2024 following earlier proceedings, and the present claim now proceeds by way of a resumed substantive hearing in the Administrative Court.

The Issues

The claim raises three principal grounds. Ground 1 challenges the deportation decision on procedural fairness and Equality Act grounds; Ground 2 challenges the lawfulness of
detention, including by reference to the Hardial Singh principles, the Secretary of State’s detention policy and Articles 3, 5 and 8 ECHR; and Ground 3 alleges a further breach of the reasonable adjustments duty in relation to detention and segregation.

In the preliminary ruling, the Secretary of State was granted permission to amend her defence in two important respects. First, in relation to Ground 1, the court granted leave to argue that paragraph 16 of Schedule 3 to the Equality Act 2010 may exclude a disability discrimination claim under section 29 in the context of immigration decision-making. Secondly, in relation to Ground 2, the court granted leave to rely on section 44 of the Border Security, Asylum and Immigration Act 2025, including its expressly retrospective effect.

Why the Case Matters

Although the court rejected the Secretary of State’s applications to treat the claim as academic or to transfer the Equality Act and false imprisonment aspects to the County Court, the ruling makes clear that the case raises novel and important issues which merit determination in the Administrative Court. The judge held that the issues are of wider public importance and likely to affect the future development of policy in relation to mentally impaired individuals in immigration decision-making and detention.

The ruling is therefore significant not because it finally resolves those issues, but because it confirms that this case will be the vehicle through which they are determined. In particular, the resumed hearing is expected to address the scope of the Schedule 3 Equality Act exclusion, the proper approach to forum where Equality Act damages claims are advanced alongside public law grounds, and the impact of section 44 BSAIA 2025 on historic detention claims.

Practical Point

This is now a case to watch closely. The Administrative Court has indicated that the issues in play are novel, complex and of wider public importance, and the resumed hearing is likely to provide authoritative guidance on the interaction between immigration decision-making, reasonable adjustments for mentally impaired individuals, and the evolving statutory framework governing immigration detention.

Matthew Howarth has extensive experience of judicial review claims in the High Court concerning the overlap between the Immigration Acts, detention decisions, deportation, asylum support and Care Act 2014 duties owed by local authorities. He was recently led by Jack Holborn in the two leading BLZ (No 1 and No 2) cases before Mr Justice Fordham, [2025] EWHC 153 (Admin) and [2024] EWHC 154 (Admin). Matthew is ranked as a Band 1 leading junior in the Legal 500 for both Immigration and Administrative & Human Rights Law.

The Judgment can be found here – https://caselaw.nationalarchives.gov.uk/ewhc/admin/2026/448