## Facts

- Following the September 11 attacks, Parliament enacted Part 4 of the Anti-terrorism, Crime and Security Act 2001 (ATCSA).
- The Home Secretary could certify non-UK nationals as suspected international terrorists and detain them indefinitely without trial when removal was not feasible (including where deportation would breach ECHR Article 3).
- The United Kingdom entered a derogation from ECHR Article 5 under ECHR Article 15, asserting a public emergency threatening the life of the nation.
- Nine non-UK nationals (and two additional appellants) were certified and detained, largely at HMP Belmarsh; none had been charged in the UK and no criminal trial was in prospect.
- The detainees challenged both the detention scheme and the derogation before the Special Immigration Appeals Commission (SIAC).
- SIAC upheld the derogation but found the detention scheme discriminatory against non-nationals under ECHR Article 14 read with Article 5; the Court of Appeal reversed and upheld the scheme.
- The detainees appealed to the House of Lords.

## Issues

1. Whether there was a “public emergency threatening the life of the nation” permitting derogation from ECHR Article 5 under ECHR Article 15.
2. Whether indefinite detention without trial of only non-nationals was “strictly required by the exigencies of the situation” for purposes of ECHR Article 15.
3. Whether limiting the detention power to non-nationals violated ECHR Article 14 in conjunction with ECHR Article 5.
4. Whether the detention provision was incompatible with Convention rights such that a declaration of incompatibility should be made under Human Rights Act 1998 (HRA) § 4.

## Decision

- By majority, the House of Lords accepted that the threat of international terrorism could amount to a public emergency for ECHR Article 15 purposes (with one Law Lord rejecting that conclusion).
- By a 7–2 majority, the House held the ATCSA detention provision incompatible with ECHR Articles 5 and 14 because it was disproportionate and unjustifiably discriminatory.
- The House issued a declaration of incompatibility under HRA § 4, concluding the provision could not be made Convention-compliant through interpretation under HRA § 3.
- The House did not order the detainees’ release; the legal consequences were left to the political branches.
- One Law Lord would have held the derogation itself invalid because the asserted emergency did not meet the “life of the nation” threshold, but still agreed the appeals should be allowed.

## Legal Principles

- Courts may give weight to executive assessments in national security matters, but whether derogating measures are “strictly required” is a legal question subject to judicial review.
- ECHR Article 15 permits derogation only in a qualifying emergency and only to the extent strictly required; measures must satisfy proportionality.
- Indefinite detention without trial directed only at non-nationals, when based on terrorism risk rather than genuine immigration control and when removal is not realistically available, can violate ECHR Article 5.
- Differential treatment based on nationality engages ECHR Article 14; it requires objective and reasonable justification, especially when nationals and non-nationals may present comparable risks.
- Where primary legislation cannot be interpreted compatibly with Convention rights without rewriting it, the proper domestic remedy is a declaration of incompatibility under HRA § 4.

## Conclusion

The House of Lords held that the post-2001 scheme authorizing indefinite executive detention without trial for suspected international terrorists, limited to non-nationals, was not strictly required and lacked justification for its nationality-based distinction; it therefore violated ECHR liberty and equality guarantees and warranted a declaration of incompatibility.


A v. Sec’y of State for the Home Dep’t, [2004] UKHL 56 (H.L. 2004)