52 BOSPHORUS HAVA YOLLARI TURİZM VE TİCARET ANONİM ŞİRKETİ v. IRELAND JUDGMENT – JOINT CONCURRING OPINION judgment should probably have explored further those situations which, admittedly, do not concern the instant case but in which the European Court of Justice allows national courts a certain discretion in implementing its judgment and which could become the subject matter of an application to the European Court of Human Rights. However, it is clear from paragraph 157 of the judgment and the reference to Cantoni v. France (judgment of 15 November 1996, Reports 1996-V) that the use of discretion in implementing a preliminary ruling by the European Court of Justice is not covered by the presumption of “equivalent protection”. On the other hand, as the judgment itself acknowledges, individuals' access to the Community court is “limited” (see paragraph 162). Yet, as the Court reiterated in Mamatkulov and Askarov v. Turkey ([GC], nos. 46827/99 and 46951/99, ECHR 2005-I), the right of individual application “is one of the keystones in the machinery for the enforcement of the rights and freedoms set forth in the Convention” (see paragraph 122 of that judgment). Admittedly, judicial protection under Community law is based on a plurality of appeals, among which the reference to the Court of Justice for a preliminary ruling has an important role. However, it remains the case that, despite its value, a reference for a preliminary ruling entails an internal, a priori review. It is not of the same nature and does not replace the external, a posteriori supervision of the European Court of Human Rights, carried out following an individual application. The right of individual application is one of the basic obligations assumed by the States on ratifying the Convention. It is therefore difficult to accept that they should have been able to reduce the effectiveness of this right for persons within their jurisdiction on the ground that they have transferred certain powers to the European Communities. For the Court to leave to the Community's judicial system the task of ensuring “equivalent protection”, without retaining a means of verifying on a case-by-case basis that that protection is indeed “equivalent”, would be tantamount to consenting tacitly to substitution, in the field of Community law, of Convention standards by a Community standard which might be inspired by Convention standards but whose equivalence with the latter would no longer be subject to authorised scrutiny. 4. Admittedly, the judgment states that such in concreto review would remain possible, since the presumption could be rebutted if, in the circumstances of a particular case, the Court considered that “the protection of Convention rights was manifestly deficient” (see paragraph 156).