EUROPEAN UNION’S LEGAL SYSTEM: SPECIFICS, MODERN TENDENCIES AND METHODOLOGICAL PRINCIPLES OF DRAFTING IN TERMS OF ADAPTING UKRAINIAN LEGISLATION TO THE EU ACQUIS

The article provides a comprehensive study of the legal system of the European Union (hereinafter – EU), which has a sui generis nature and combines the features of both international and supranational legal orders. It is emphasized that the enlargement of the EU and the growing influence of its law necessitate the adaptation of the national legal systems of candidate states, including Ukraine, to the acquis of the EU. The structural elements of the EU legal system are revealed, namely its multi-level and multidimensional character, as well as its interaction with national and international law. Particular attention is devoted to the fundamental doctrines developed in the case law of the Court of Justice of the EU: autonomy of the legal order, supremacy, direct effect, and the preliminary ruling procedure under Article 267 of the Treaty on the Functioning of the European Union (TFEU), which ensure the unity of interpretation and application of EU law. Approaches to the classification of EU sources of law are systematized: founding treaties and general principles (primary law); regulations, directives, and decisions (secondary law); soft law instruments; and case law of the Court of Justice of the EU. The distinction between “direct applicability” and “direct effect” is clarified, as well as the relationship between the supremacy of EU law and the internal hierarchy of sources. The article identifies the current trends in the development of the EU legal system, including: the universalization and unification of law; the strengthening of interdependence between international, regional, and national legal orders; the constitutionalization of the EU legal order; and the expansion of EU competences in the fields of digitalization, cybersecurity, environmental protection, and healthcare. The role of the fundamental values enshrined in Article 2 of the Treaty on European Union (TEU) and the Charter of Fundamental Rights of the EU, as well as the mechanisms for their enforcement (procedure under Article 7 TEU, budgetary conditionality instruments), is highlighted. Special emphasis is placed on the regulatory benchmarks of the digital transformation: the General Data Protection Regulation (GDPR), the Digital Services Act (DSA), the Digital Markets Act (DMA), the NIS2 Directive, the Data Act, and the Artificial Intelligence Act (AI Act), which set specific requirements for the adaptation of Ukrainian draft legislation. The scientific novelty of the article lies in formulating an original model of adaptation of Ukrainian legislation to the acquis of the EU, which covers three interrelated levels: 1) theoretical – conceptualizing the nature and doctrinal foundations of EU law; 2) methodological – integrating the instruments of “better regulation”, including regulatory impact assessment (RIA), the SME test, the “one in, one out” principle, and the prevention of gold-plating; 3) institutional and practical – the establishment of a Parliamentary Office for Law-Making, which does not duplicate the competences of the Main Scientific and Expert Department of the Secretariat of the Verkhovna Rada of Ukraine (MSED), but focuses on methodology, compliance with the acquis, and terminological unification. It is demonstrated that the combination of doctrinal benchmarks of EU law with practical methodological instruments forms a new quality of Ukrainian law-making. It is concluded that the successful adaptation of Ukrainian legislation to the acquis of the EU requires not only formal harmonization of norms but also the development of a coherent methodology of law-making that combines European standards of legislative practice with national legal traditions, ensures terminological consistency, and provides for post-legislative monitoring. The implementation of this model will contribute to strengthening Ukraine’s institutional resilience, improving the quality of legislative work, and ensuring its compliance with European standards under the conditions of contemporary global challenges.