Opinion of Advocate General Saugmandsgaard Øe delivered on 5 June 2018.

XC and Others v Generalprokuratur.#Request for a preliminary ruling from the Oberster Gerichtshof.#Reference for a preliminary ruling — Principles of EU law — Sincere cooperation — Procedural autonomy — Principles of equivalence and effectiveness — National legislation laying down a remedy allowing criminal proceedings to be reheard in the event of infringement of the European Convention for the Protection of Human Rights and Fundamental Freedoms — No obligation to extend that procedure to cases of alleged infringement of the fundamental rights enshrined in EU law.#Case C-234/17.