Key facts of the case:
Reference for a preliminary ruling — European Union Citizenship — Articles 18 and 21 TFEU — Request to a Member State by a third country seeking extradition of an EU citizen who is a national of another Member State and who has exercised his right to free movement in the first Member State — Request made for the purpose of enforcing a custodial sentence and not for the purpose of prosecution — Prohibition on extradition applied only to own nationals — Restriction on free movement — Justification based on the prevention of impunity — Proportionality.
Outcome of the case:
On those grounds, the Court (Grand Chamber) hereby rules:
Articles 18 and 21 TFEU must be interpreted as meaning that, where an extradition request has been made by a third country for an EU citizen who has exercised his right to free movement, not for the purpose of prosecution, but for the purpose of enforcing a custodial sentence, the requested Member State, whose national law prohibits the extradition of its own nationals out of the European Union for the purpose of enforcing a sentence and makes provision for the possibility that such a sentence pronounced abroad may be served on its territory, is required to ensure that that EU citizen, provided that he resides permanently in its territory, receives the same treatment as that accorded to its own nationals in relation to extradition.
49) It must also be stated that, in the event that the requested Member State intends to extradite a national from another Member State at the request of a third country, the first Member State must check that the extradition will not infringe the rights guaranteed by the Charter of Fundamental Rights of the European Union, in particular Article 19 (see, to that effect, judgment of 6 September 2016, Petruhhin, C‑182/15, EU:C:2016:630, paragraph 60).