Principle of subsidiarity

The principle of subsidiarity is defined in Article 5(3) of the Treaty on European Union. It aims to ensure that decisions are taken at the closest possible level to the citizen and that constant checks are made to verify that action at the European Union (EU) level is justified in light of the possibilities available at the national, regional or local level.

Specifically, it is the principle whereby the EU does not take action (except in the areas that fall within its exclusive jurisdiction), unless it is more effective than action taken at the national, regional or local level.

It is closely linked to the principle of proportionality, which requires that any action taken by the EU not go beyond what is necessary to achieve the aims of the treaties. Another related principle, the principle of conferral, states that any policy areas not explicitly agreed in the treaties by all EU Member States remain in their domain.

There are two relevant protocols annexed to the Treaty of Lisbon:

Protocol No 1 on the role of national parliaments encourages national parliaments’ involvement in EU activities, and requires EU documents and proposals to be forwarded promptly to them so they can examine them before the Council of the European Union makes a decision.
Protocol No 2 requires the European Commission to take into account the regional and local dimension of all draft legislative acts and to make a detailed statement on how the principle of subsidiarity is respected. This protocol allows national parliaments to object to a proposal on the grounds that it breaches the principle, as a result of which the proposal must be reviewed and may be maintained, amended or withdrawn by the Commission or blocked by the European Parliament or the Council.

In the event of a breach of the principle of subsidiarity, the European Committee of the Regions or Member States may refer an adopted act directly to the Court of Justice of the European Union.