60 A. AND OTHERS v. THE UNITED KINGDOM JUDGMENT (f) the lawful arrest or detention of a person ... against whom action is being taken with a view to deportation or extradition.” Article 15 of the Convention states: “1. In time of war or other public emergency threatening the life of the nation any High Contracting Party may take measures derogating from its obligations under [the] Convention to the extent strictly required by the exigencies of the situation, provided that such measures are not inconsistent with its other obligations under international law. 2. No derogation from Article 2, except in respect of deaths resulting from lawful acts of war, or from Articles 3, 4 (paragraph 1) and 7 shall be made under this provision. 3. Any High Contracting Party availing itself of this right of derogation shall keep the Secretary General of the Council of Europe fully informed of the measures which it has taken and the reasons therefore. It shall also inform the Secretary General of the Council of Europe when such measures have ceased to operate and the provisions of the Convention are again being fully executed.” A. The parties’ submissions 1. The applicants 140. The applicants objected that before the domestic courts the Government had not sought to argue that they were detained as “person[s] against whom action is being taken with a view to deportation or extradition”, but had instead relied on the derogation under Article 15. In these circumstances, the applicants contended that it was abusive and contrary to the principle of subsidiarity for the Government to raise a novel argument before the Court and that they should be stopped from so doing. 141. In the event that the Court considered that it could entertain the Government’s submission, the applicants emphasised that the guarantee in Article 5 was of fundamental importance and exceptions had to be strictly construed. Where, as in their case, deportation was not possible because of the risk of treatment contrary to Article 3 in the receiving country, Article 5 § 1 (f) would not authorise detention, irrespective of whether the individual posed a risk to national security. Merely keeping the possibility of deportation under review was not “action ... being taken with a view to deportation”; it was action, unrelated to any extant deportation proceedings, that might make the deportation a possibility in the future. Detention pursuant to such vague and non-specific “action” would be arbitrary. Moreover, it was clear that during the periods when the applicants’ cases were being considered by SIAC on appeal (July 2002-October 2003), the Government’s position was that they could not be deported compatibly with Article 3 and that no negotiations to effect deportation should be attempted