The Principle of Sincere Cooperation in the European Union in Nationality Matters

Abstract

This paper examines the principle of the European Union of sincere cooperation, with particular emphasis on its implications for nationality—a domain traditionally within the exclusive competence of Member States. It first outlines the development and legal significance of the principle, then considers its application in areas where national and Union interests intersect, using nationality as a focal point. The analysis centres on Commission v. Malta, a landmark case before the Court of Justice of the EU, in which the Commission contested Malta’s investor citizenship scheme. The scheme allowed individuals to acquire Maltese nationality without demonstrating a genuine link to the state, which the Commission argued contravened the principle of sincere cooperation, although neither international nor EU law mandates a genuine link in nationality laws. Given the impact that a Member State’s citizenship policies can have on other Member States through the concept of Union citizenship, the paper critically assesses whether such a link could be required under EU law. It concludes that imposing this requirement could unjustifiably infringe on national autonomy, as any “extension” of Union competence through the loyalty clause should only occur to facilitate Union tasks. Analysing Commission v. Malta, the paper finds that the Court linked sincere cooperation to the concept of solidarity and reconceptualised the genuine link by introducing a more flexible and legally ambiguous notion of a “special relationship of solidarity and good faith.” The Court’s reasoning thus rests on elusive concepts that risk enabling judicial expansion into other areas formally reserved to the Member States.