Opinion of Advocate General Szpunar delivered on 14 December 2023.#S.Ö. and Others v Stadt Duisburg and Others.#Requests for a preliminary ruling from the Verwaltungsgericht Düsseldorf.#Reference for a preliminary ruling – Citizenship of the Union – Article 20 TFEU – Nationality of a Member State and of a third country – Acquisition of the nationality of a third country – Loss of the nationality of a Member State and of citizenship of the Union by operation of law – Possibility of applying to retain the nationality of the Member State prior to acquisition of the nationality of a third country – Individual examination of the consequences of the loss of the nationality of the Member State in the light of EU law – Scope.#Joined Cases C-684/22 to C-686/22.