Indefinite detention of alleged foreign terrorists given the impossibility of deportation. Proportionality and temporary nature of measures derogating from the European Convention on Human Rights in time of emergency. Nature and degree of the public emergency. Margin of appreciation of Contracting States in derogating from the Convention.
Art. 15 ECHR
Art. 5 ECHR
1. The indefinite detention of non-nationals, who are suspected of international terrorism-related activities and who cannot be deported because of the risk of ill-treatment in their destination countries, breaches Article 5, para. 1 ECHR. The derogating measures adopted pursuant to Article 15 ECHR by the United Kingdom are disproportionate, since they discriminate unjustifiably between national and non-nationals. States may take measures derogating from their obligations under the Convention only “to the extent strictly required by the exigencies of the situation”.
2. Although a “public emergency” should be actual or imminent in order to justify a derogation from the Convention pursuant to Article 15 ECHR, such a condition has to be read broadly. It follows that States can adopt derogating measures also before having suffered a direct attack. The purpose of the derogation clause is to allow the protection of populations from future risks.
3. Contracting States have a wide margin of appreciation both as regards the decision to call a state of emergency pursuant to Article 15 ECHR and as regards the choice of the measures needed to face it. However, national authorities do not enjoy an unlimited power in this respect. It is for the Court to rule whether the measures adopted have gone beyond the extent strictly required by the exigencies of the situation and if adequate safeguards have been provided against potential abuses. In doing so, the Court must take into consideration the nature of the rights affected by the derogation, the circumstances leading to the emergency situation and its duration.
4. Derogating measures cannot be said to be invalid on the ground that they are not temporary, since it is possible for a public emergency within the meaning of Article 15 ECHR to continue for many years. However, the question of a proportional response by the States implies to consider the duration of the emergency.
5. In determining the nature and degree of the actual or imminent threat to the life of the nation pursuant to Article 15 ECHR, a broad range of factors has to be taken into account. Emergency situations exist even though the functioning of institutions is not gravely endangered.
In so ruling, the Court followed the line of a decision of the House of Lords that had already found the derogating measures adopted by the United Kingdom under Article 15 ECHR to be unlawful.
House of Lords, Opinions of the Lords of Appeal for Judgment in the Cause A (FC) and others (FC) (Appellants) v. Secretary of State for the Home Department (Respondent) and X (FC) and another (FC) (Appellants) v. Secretary of State for the Home Department (Respondent), 16 December 2004, Session 2004-5,  UKHL 56.