General principles of European Union law

The general principles of European Union law are general principles of law which are applied by the European Court of Justice and the national courts of the member states when determining the lawfulness of legislative and administrative measures within the European Union. General principles of European Union law may be derived from common legal principles in the various EU member states, or general principles found in international law or European Union law. General principles of law should be distinguished from rules of law as principles are more general and open-ended in the sense that they need to be honed to be applied to specific cases with correct results.

The general principles of European Union law are rules of law which a European Union judge, sitting for example in the European Court of Justice, has to find and apply but not create. Particularly for fundamental rights, Article 6(3) of the Treaty on European Union provided:

Fundamental rights, as guaranteed by the European Convention for the Protection of Human Rights and Fundamental Freedoms and as they result from the constitutional traditions common to the Member States, shall constitute general principles of the Union's law.

Further, Article 340 of the Treaty on the Functioning of the European Union (formerly Article 215 of the Treaty establishing the European Economic Community) expressly provides for the application of the "general principles common to the laws of the Member States" in the case of non-contractual liability.

In practice the European Court of Justice has applied general principles to all aspects of European Union law. In formulating general principles, European Union judges draw on a variety of sources, including: public international law and its general principles inherent to all legal systems; national laws of the member states, that is general principles common to the laws of all member states, general principles inferred from European Union law, and fundamental human rights. General principles are found and applied to avoid the denial of justice, fill gaps in European Union law and to strengthen the coherence of European Union law.

Accepted general principles of European Union Law include fundamental rights, proportionality, legal certainty, equality before the law and subsidiarity. In Case T-74/00 Artegodan, the General Court (then Court of First Instance) appeared willing to extrapolate from the limited provision for the precautionary principle in environmental policy in Article 191(2) TFEU to a general principle of EU law.