Snapshot

EU law is an autonomous legal order with features of both international and domestic law. Two judgments in the 1960s established its operating logic: direct effect (Van Gend en Loos, 1963) allows qualifying EU provisions to be invoked before national courts, and primacy (Costa v ENEL, 1964) requires conflicting national rules to give way within the scope of EU law.

Legal Anchors

• •TEU Article 5 — conferral, subsidiarity, proportionality.
• •TFEU Article 288 — types of legal acts (regulation, directive, decision, recommendation, opinion).
• •TFEU Article 290 — delegated acts.
• •TFEU Article 291 — implementing acts.
• •TFEU Article 263 — actions for annulment against EU acts.
• •TFEU Article 267 — preliminary references (interpretation of EU law by the CJEU).

Why It Matters

The form of an EU act affects its legal operation. A regulation is directly applicable from the date specified in the act; a directive binds member states as to the result to be achieved; a decision is binding in its entirety and, where it identifies addressees, binds only them; recommendations and opinions have no binding force. Justiciability and routes of challenge also depend on the provision, act and applicant concerned.

Core Concepts — Reorganised by Theme

1. Sources and hierarchy. EU law includes several categories of norms:

• •Primary law — the TEU, TFEU and Euratom Treaty, together with their protocols and annexes. The Charter of Fundamental Rights has the same legal value as the treaties. General principles of EU law also serve as standards for reviewing Union action.
• •International agreements concluded by the EU — binding on the Union institutions and member states under Article 216(2) TFEU; secondary legislation must comply with them.
• •Secondary law — the acts listed in Article 288 TFEU: regulations, directives, decisions, recommendations and opinions. Legislative acts are adopted by a legislative procedure; delegated and implementing acts are non-legislative acts adopted under Articles 290 and 291 TFEU.
• •National implementing measures — remain national law even when they transpose directives or implement other EU obligations.

2. Primary law in detail. The TEU contains the Union's values, objectives, institutional framework, foreign-policy provisions and accession and withdrawal rules. The TFEU sets out institutional procedures, competences and detailed policy provisions. The two treaties have equal legal value (TEU Article 1, third paragraph). The Charter and the Euratom Treaty complete the principal framework of primary law. Treaty amendment follows Article 48 TEU — see Chapter 17.

3. The five secondary acts decomposed.

• •Regulation — binding in its entirety and directly applicable in all member states. No national transposition is required. For example, the General Data Protection Regulation (Regulation 2016/679) became applicable on 25 May 2018.
• •Directive — binding as to the result; each member state chooses form and methods. The transposition period is specified in the directive. After that period expires, a sufficiently clear, precise and unconditional provision may be invoked against the state under the doctrine of vertical direct effect, illustrated by Marshall v Southampton (1986). Directives do not of themselves have horizontal direct effect between private parties, although national courts must interpret national law consistently with a directive so far as possible.
• •Decision — binding in its entirety. A decision that specifies addressees is binding only on them. Example: a Commission antitrust decision addressed to a company.
• •Recommendation — not binding. A soft-law instrument suggesting a course of action.
• •Opinion — not binding. Used to express a position.

4. Delegated vs. implementing acts. Lisbon split what used to be "comitology" into two cleaner categories.

• •Delegated acts (Article 290 TFEU) — the Commission, acting under a delegation from the legislator (Parliament + Council), can adopt non-legislative acts that supplement or amend non-essential elements of the original legislative act. Parliament or Council can revoke the delegation or object to a specific act within a set period. Useful for technical updates (e.g. updating annexes of substance lists).
• •Implementing acts (Article 291 TFEU) — when uniform implementation across all member states requires it, the Commission (or, exceptionally, the Council) adopts implementing acts. Member-state experts oversee this through committees (the comitology procedures: advisory and examination).

5. Foundational judicial principles. Three CJEU rulings shaped the system more than any treaty article:

• •Van Gend en Loos (Case 26/62, 1963) — direct effect. Sufficiently clear and unconditional EU provisions create rights that individuals can invoke before national courts.
• •Costa v ENEL (Case 6/64, 1964) — primacy. The Court held that law stemming from the EEC Treaty could not be overridden by domestic legal provisions without undermining the Community legal order. The dispute arose after Italy nationalised its electricity industry.
• •Francovich (Joined Cases C-6/90 and C-9/90, 1991) — established state liability for loss caused by a member state's breach of EU law. Later case law expressed the general conditions as a rule intended to confer rights, a sufficiently serious breach and a direct causal link between the breach and the loss.

6. Competences — who is allowed to act.

• •Exclusive competence (Article 3 TFEU) — only the EU can legislate; member states act only when empowered by the Union or when implementing Union acts. It covers the customs union, competition rules necessary for the internal market, monetary policy for member states whose currency is the euro, the common commercial policy, and conservation of marine biological resources under the common fisheries policy. The Union also has exclusive competence to conclude certain international agreements in the circumstances defined by Article 3(2).
• •Shared competence (Article 4 TFEU) — both EU and member states can legislate; member states act where the EU has not yet acted ("pre-emption"). Covers the internal market, social policy (defined aspects), economic, social and territorial cohesion, agriculture and fisheries (other than conservation), environment, consumer protection, transport, trans-European networks, energy, the Area of Freedom, Security and Justice, and common safety concerns in public-health matters (defined aspects).
• •Supporting competence (Article 6 TFEU) — the EU supports, coordinates or supplements member-state action without harmonising. Covers protection and improvement of human health, industry, culture, tourism, education, vocational training, youth and sport, civil protection, and administrative cooperation.
• •Special-regime competences — economic and employment policy coordination (Article 5 TFEU) and the CFSP (Articles 23–46 TEU) sit outside this trichotomy.

7. Cardinal principles for institutional action. Article 5 TEU sets three:

• •Conferral — the EU acts only within the powers conferred on it by the treaties.
• •Subsidiarity — in areas that do not fall within exclusive EU competence, the Union acts only if the objectives cannot be sufficiently achieved by the member states and can, by reason of the scale or effects of the proposed action, be better achieved at Union level.
• •Proportionality — the content and form of EU action must not exceed what is necessary.

The Court also applies general principles including legal certainty, non-retroactivity of penal provisions, equality before the law, legitimate expectations, the rights of the defence and good administration. Loyal cooperation is expressly stated in Article 4(3) TEU and binds the Union and the member states.

Numbers & Dates

Recent Developments

National constitutional judgments have disputed aspects of primacy, including the German Federal Constitutional Court's 2020 PSPP/Weiss judgment and the Polish Constitutional Tribunal's 2021 judgment in case K 3/21. The Commission used infringement proceedings in response to the Polish judgment. Separately, Regulation 2020/2092 permits budget-protection measures where breaches of rule-of-law principles affect or seriously risk affecting the sound financial management of the Union budget or the protection of the Union's financial interests; the CJEU upheld that regulation in 2022.

Common Confusions

• •"Directly applicable" (a property of regulations: no national act needed) is not the same as "direct effect" (a property of an EU provision: it creates rights individuals can invoke). A regulation is directly applicable; a treaty article or even a directive provision can have direct effect.
• •The supremacy principle is not in the body of the treaties — it lives in Declaration No. 17 attached to the Final Act of the Lisbon IGC, which incorporates the case law. The Court of Justice did the constitutional work.
• •"Implementing act" (Article 291) is a different beast from "implementing legislation in a member state" (the national act transposing a directive).

Capsule Glossary

• •Direct effect — capacity of an EU provision to be invoked by individuals before national courts.
• •Supremacy / primacy — EU law prevails over conflicting national law.
• •Conferral — EU acts only within powers conferred by the treaties.
• •Comitology — committee-based oversight of Commission implementing acts.
• •Acte clair — exception to the obligation to refer a preliminary question when the answer is so obvious that no reasonable doubt exists.
• •Plaumann test — strict standing requirement for private parties bringing an annulment action under Article 263 TFEU.

Cross-References

• •Preliminary references and the Court's structure → Chapter 7
• •The Charter as primary law → Chapter 3
• •Legislative procedures that produce these acts → Chapter 9
• •Rule-of-law mechanisms → Chapter 17

Primary Sources

• •TFEU, Article 288 — eur-lex.europa.eu
• •Costa v ENEL (Case 6/64) judgment — eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:61964CJ0006
• •Van Gend en Loos (Case 26/62) judgment — curia.europa.eu
• •Francovich (Joined Cases C-6/90 and C-9/90) judgment — curia.europa.eu
• •Commission infringement action concerning Poland's Constitutional Tribunal — ec.europa.eu

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