Judgment of the Court (First Chamber) of 28 September 2023.#European Commission v United Kingdom of Great Britain and Northern Ireland.#Failure of a Member State to fulfil obligations – Judgment of the Court finding a failure to fulfil obligations – Failure to comply with the judgment – Directive 95/60/EC – Fiscal marking of gas oils – Agreement on the withdrawal of the United Kingdom of Great Britain and Northern Ireland from the European Union and the European Atomic Energy Community – Protocol on Ireland and Northern Ireland – Continuation of the infringement after the end of the transition period as regards Northern Ireland – Article 260(2) TFEU – Pecuniary penalties – Lump sum – Gravity of the infringement