Sufficiently Serious Breach in EU Law: Balancing Vagueness and Legal Certainty

The concept of a “sufficiently serious breach of law” is critical in EU law for determining non-contractual liability and securing compensation for damages. As a legally vague term, it allows for broad interpretive leeway, granting courts the flexibility to consider individual circumstances, but simultaneously introduces challenges in predictability and the principle of legitimate expectations—a cornerstone of EU law. This article examines the term’s ambiguity and how it enables both adaptability within the EU’s complex legal system and a degree of legal uncertainty. Through an analysis of the Court of Justice of the European Union (CJEU) case law, the article seeks to clarify the methodological approach to identifying a sufficiently serious breach. The study identifies criteria such as the scope of discretion, clarity of regulations, and excitability, all pivotal in determining the term’s applicability and ensuring the consistent, fair treatment of Member States’ obligations. Additionally, the article addresses gaps in current literature, specifically the need for a comprehensive view that extends beyond isolated case analyses, aiming to offer clarity on the term’s evolving interpretation and its impact on the CJEU’s decision-making.