THE PRINCIPLE OF THE RULE OF LAW IN THE LEGAL SYSTEMS OF THE EU AND UKRAINE: A COMPARATIVE LEGAL ANALYSIS

The article presents a comparative legal analysis of the principle of the rule of law in the legal systems of the European Union and Ukraine, taking into account contemporary integration processes and Ukraine’s orientation toward alignment with the acquis communautaire. The rule of law is one of the fundamental principles for building a democratic state governed by the rule of law and ensuring the supremacy of human rights. In EU law, it serves as a system-forming constitutional principle that guarantees the unity and primacy of European Union law over the national legislation of Member States, including constitutional norms. The article analyzes key rulings of the Court of Justice of the European Union (Costa v. ENEL, Internationale Handelsgesellschaft, Simmenthal), which laid the foundation for the doctrine of EU law supremacy. Particular attention is given to the concept of direct effect of acquis communautaire norms, which enables individuals and legal entities to invoke EU law to protect their rights even in the absence of national implementing legislation. In Ukraine’s legal order, the principle of the rule of law is enshrined in the Constitution (Article 8), but it is largely declarative and lacks a detailed framework for implementation. Judicial practice in Ukraine demonstrates inconsistency in the application of this principle: it is often invoked in a formalistic manner without substantive analysis or reasoning. The article emphasizes the importance of distinguishing between formal and substantive approaches to interpreting the rule of law, highlighting the need for consistent implementation of European standards in the legal practice of Ukrainian courts. Based on the conducted analysis, the article concludes that there is a structural difference in the conceptualization, normative formulation, and practical implementation of the rule of law in the European Union and Ukraine. This discrepancy is identified as a significant barrier to Ukraine’s effective legal integration into the European legal space. The author proposes that the doctrine of the Court of Justice of the European Union – supported by the principles of direct effect and the primacy of EU law – should serve as a model for Ukraine’s gradual institutional convergence with the EU.