Judgment of the Court (Fifth Chamber) of 14 March 2024.#European Commission v United Kingdom of Great Britain and Northern Ireland.#Failure of a Member State to fulfil obligations – Default procedure – Agreement on the withdrawal of the United Kingdom of Great Britain and Northern Ireland from the European Union and the European Atomic Energy Community – Article 127(1) – Transition period – Jurisdiction of the Court of Justice – Judgment of the Supreme Court of the United Kingdom – Enforcement of an arbitral award granting the payment of compensation – Decision of the European Commission declaring that that payment constitutes State aid which is incompatible with the internal market – Article 4(3) TEU – Sincere cooperation – Obligation to stay proceedings – First paragraph of Article 351 TFEU – International agreement between Member States and third countries concluded before the date of their accession to the European Union – Convention on the Settlement of Investment Disputes between States and Nationals of Other States (ICSID Convention) – Application of EU law – Article 267 TFEU – National court or tribunal adjudicating at last instance – Obligation to make a reference to the Court for a preliminary ruling – Article 108(3) TFEU – Suspension of implementation of the aid.#Case C-516/22.