70 OTHMAN (ABU QATADA) v. THE UNITED KINGDOM JUDGMENT B. Admissibility 214. The Court notes that this complaint is linked to the applicant’s substantive Article 3 complaint and must therefore likewise be declared admissible. C. Merits 215. The requirements of Article 13 in the context of an arguable Article 3 claim were recently set out in A. v. the Netherlands, cited above, §§ 155-158, which concerned the proposed expulsion of a terrorist suspect to Libya: “155. The Court reiterates that Article 13 guarantees the availability at the national level of a remedy to enforce – and hence to allege non-compliance with – the substance of the Convention rights and freedoms in whatever form they might happen to be secured in the domestic legal order and bearing in mind that Contracting States are afforded some discretion as to the manner in which they conform to their obligations under this provision (see Shamayev and Others v. Georgia and Russia, no. 36378/02, § 444, ECHR 2005 III). For Article 13 to be applicable, the complaint under a substantive provision of the Convention must be arguable. In view of the above finding under Article 3, the Court considers that the applicant’s claim under Article 3 was “arguable” and, thus, Article 13 was applicable in the instant case. 156. The Court further reiterates that the remedy required by Article 13 must be effective both in law and in practice, in particular in the sense that its exercise must not be unjustifiably hindered by the acts or omissions of the authorities of the respondent State (see Shamayev and Others, cited above, § 447). The Court is not called upon to review in abstracto the compatibility of the relevant law and practice with the Convention, but to determine whether there was a remedy compatible with Article 13 of the Convention available to grant the applicant appropriate relief as regards his substantive complaint (see, among other authorities, G.H.H. and Others v. Turkey, no. 43258/98, § 34, ECHR 2000-VIII). The “effectiveness” of a “remedy” within the meaning of Article 13 does not depend on the certainty of a favourable outcome for the applicant (Čonka v. Belgium, no. 51564/99, § 75, ECHR 2002 I; and Onoufriou v. Cyprus, no. 24407/04, §§ 119-121, 7 January 2010). 157. The Court further points out that the scope of the State’s obligation under Article 13 varies depending on the nature of the applicant’s complaint under the Convention. Given the irreversible nature of the harm that might occur if the alleged risk of torture or ill-treatment materialised and the importance which the Court attaches to Article 3, the notion of an effective remedy under Article 13 requires (i) independent and rigorous scrutiny of a claim that there exist substantial grounds for believing that there was a real risk of treatment contrary to Article 3 in the event of the applicant’s expulsion to the country of destination, and (ii) the provision of an effective possibility of suspending the enforcement of measures whose effects are potentially irreversible (see Shamayev and Others, cited above, § 460; Olaechea Cahuas v. Spain, no. 24668/03, § 35, ECHR 2006-X; and Salah Sheekh v. the Netherlands, no. 1948/04, § 154, ECHR 2007 I).