The European Union has a special legal system that applies to all 27 member countries. It is called supranational law because it stands above national laws in certain areas. When EU law and a country’s own law disagree, EU law always wins. This rule, known as supremacy, makes sure the same rules apply everywhere in the EU. It helps create one united market and brings countries closer together, even though each has its own history and traditions.
For example, if an EU rule says cars must meet strict safety standards, a member country cannot allow weaker national standards to protect its own car makers. Or if EU law bans unfair taxes on goods from other EU countries, a national government cannot keep those taxes to help local shops. This supremacy ensures fair trade, protects people’s rights, and keeps rules the same across borders.
Supremacy in Practice
In fields such as the internal market (e.g., free movement of goods), environmental protection, workers’ rights (including equal pay), and consumer safety, EU law overrides national rules. For instance:
- Member states cannot impose bans on imports from other EU countries to shield domestic industries.
- They must adhere to EU pollution standards, even if stricter than national ones.
- EU anti-discrimination rules prevail over weaker national protections.
- EU product safety requirements apply directly.
Landmark Cases
Landmark CJEU cases shaped the foundations of EU law and continue to evolve it. Early rulings established core principles: In Van Gend en Loos (1963), the Court held that EU Treaty provisions can have direct effect, giving individuals enforceable rights in national courts and creating a new legal order for citizens.
In Costa v. ENEL (1964), it declared supremacy of EU law, meaning it overrides conflicting national laws, as member states accept limits on their sovereignty by joining the EU. Later cases like Simmenthal (1978) required national courts to set aside conflicting domestic rules, while Defrenne v. SABENA (1976) extended direct effect to equal pay rights for workers.
In 2025, the Court advanced key areas: Denmark v. Parliament and Council (C-19/23) mostly upheld the Adequate Minimum Wages Directive to support collective bargaining and fair wages, but struck parts on wage criteria as beyond EU pay competence.
Commission v. Poland (C-448/23) ruled Poland’s Constitutional Tribunal lacks independence, violating EU rule-of-law, primacy, and binding judgments. BSH v. Electrolux (C-339/22) broadened cross-border patent rulings to cover infringements even when validity is challenged. GDPR cases included EDPS v. SRB (C-413/23 P) clarifying pseudonymised data is not always personal if re-identification is unrealistic, and Russmedia (C-492/23) treating online platforms as controllers for user content, expanding data protection duties.
Sources of EU Law
EU law derives from three main categories:
- Primary legislation — The foundational treaties, especially the Treaty on European Union (TEU) and the Treaty on the Functioning of the European Union (TFEU), which serve as the EU’s “constitution.”
- Secondary Legislation
These are laws made by EU institutions based on the treaties.
- Regulations: They apply directly and fully in every member country right away. No need for national governments to make new laws to put them into effect.
- Directives: They set goals that all member countries must reach. But each country can decide how to achieve those goals in its own laws.
- Decisions: They are binding only on the specific people, companies, or countries they are addressed to.
- Non-binding instruments: These include recommendations and opinions. They give guidance or suggestions but are not legally required.
- Supplementary sources — Include general principles of law (e.g., fundamental rights, proportionality), international agreements concluded by the EU, and CJEU case law, which interprets and enforces the rules.
Hierarchy of Norms
- Treaties (primary law) form the supreme constitutional foundation.
- Secondary acts follow, with regulations having immediate, direct effect.
- CJEU rulings ensure consistent interpretation and uphold supremacy.
Core Principles
- Supremacy — National law yields to EU law in conflicts.
- Direct effect — Many EU provisions (especially treaty articles and regulations) grant individuals enforceable rights in national courts.
- Subsidiarity and proportionality — The EU acts only where member states cannot achieve objectives effectively alone, and actions must be limited to what is necessary.
Key Policy Areas
EU law shapes:
- The internal market — Free movement of goods, services, capital, and persons.
- Competition law — Combating cartels, abuse of dominance, and state aid rules.
- Environmental law — Standards for sustainability, climate action, and pollution control.
- Social policy — Workers’ rights, gender equality, and anti-discrimination.
- Area of freedom, security, and justice — Cooperation on asylum, immigration, and cross-border crime.
EU Institutions Involved in Law-Making and Enforcement
- European Parliament — Represents citizens; co-legislates with the Council.
- Council of the European Union — Represents member states’ governments.
- European Commission — Proposes laws and monitors compliance (“guardian of the treaties”).
- Court of Justice of the European Union (CJEU) — Interprets EU law and resolves disputes, ensuring uniform application.
Impact on Member States
EU law becomes part of every member country’s own legal system. National courts must apply and enforce EU rules directly, just like their own laws. This creates one big shared market where goods, services, people, and money move freely, helping businesses grow and creating jobs.
It also protects people’s basic rights, keeps competition fair, and supports joint work on important issues like cleaner environment, better worker rights, and safer borders. While countries keep their own independence in many areas, they share power on EU matters for everyone’s benefit. This mix brings more peace, economic strength, and stability across Europe.
Conclusion
European Union law forms a unique and powerful legal system that binds its 27 member states together. Through the core principles of supremacy and direct effect, EU rules take priority over national laws and allow individuals to enforce their rights directly in courts. Built on treaties, regulations, directives, and CJEU judgments, it creates a single market, protects fundamental rights, ensures fair competition, and promotes cooperation in areas like the environment, justice, and social policy.
This framework balances national sovereignty with shared European goals, fostering peace, economic strength, and stability across the continent. By enabling uniform application of laws while respecting diversity, EU law continues to drive deeper integration and a more prosperous future for all member states.
