Is the relationship between the EU judiciary and the Member State judiciaries a federal one; and if so, is it 'dual' or 'cooperative'? Federalism generally means duplex regimen: within a Union of States, the tasks of government are divided between two levels of government each of which endowed with its own institutions.1 This institutional duplication will, in its most extensive form, apply to all three branches of government: the legislature, the executive, and the judiciary. With regard to the judicial function, two institutional judiciaries may thus simultaneously coexist. A Union judiciary and a State judiciary each interpreting and applying the law within their respective jurisdiction; and depending on how these jurisdictions are divided, two federal models can be distinguished.

Published online: 19 December 2023

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