WIEDER AND GUARNIERI v. THE UNITED KINGDOM JUDGMENT were subject to judicial review. Accordingly, at the time the applicants lodged their applications with the Court the decision of the IPT was final. (ii) The Court’s assessment (α) General principles 63. It is a fundamental feature of the machinery of protection established by the Convention that it is subsidiary to the national systems safeguarding human rights (see Vučković and Others v. Serbia (preliminary objection) [GC], nos. 17153/11 and 29 others, § 69, 25 March 2014). 64. States are dispensed from answering before an international body for their acts before they have had an opportunity to put matters right through their own legal system, and those who wish to invoke the supervisory jurisdiction of the Court as concerns complaints against a State are thus obliged to use first the remedies provided by the national legal system (see, among many authorities, Vučković and Others, cited above, § 70 and Akdivar and Others v. Turkey, 16 September 1996, § 65, Reports of Judgments and Decisions 1996-IV). 65. The obligation to exhaust domestic remedies therefore requires an applicant to make normal use of remedies which are available and sufficient in respect of his or her Convention grievances. The existence of the remedies in question must be sufficiently certain not only in theory but in practice, failing which they will lack the requisite accessibility and effectiveness (see Vučković and Others, cited above, § 71 and Akdivar and Others, cited above, § 66). The exhaustion of domestic remedies is normally determined at the date on which the application is lodged with the Court (Baumann v. France, no. 33592/96, § 47, ECHR 2001-V (extracts)). 66. The Court has frequently underlined the need to apply the exhaustion rule with some degree of flexibility and without excessive formalism (see Vučković and Others, cited above, § 76 and Akdivar and Others, cited above, § 69). It would, for example, be unduly formalistic to require applicants to exhaust a remedy which even the highest court of their country would not oblige them to exhaust (see D.H. and Others v. the Czech Republic [GC], no. 57325/00, §§ 117 and 118, ECHR 2007‑IV). 67. As regards the burden of proof, it is incumbent on the Government claiming non-exhaustion to satisfy the Court that the remedy was an effective one, available in theory and in practice at the relevant time (see Vučković and Others, cited above, § 77 and Akdivar and Others, cited above, § 68). (β) Application of the general principles to the case at hand 68. In the present case the Court is not being called upon to determine whether the applicants were required to exhaust a new remedy which came into being after they lodged their applications with the Court (compare, for example, Demopoulos and Others v. Turkey (dec.) [GC], nos. 46113/99 20