The principle of conferral
is a fundamental principle of European Union law
. According to this principle, the EU is a union of member states, and all its competences
are voluntarily conferred on it by its member states. The EU has no competences by right, and thus any areas of policy not explicitly agreed in treaties by all member states remain the domain of the member states.
This principle has always underpinned the European Union, but it was explicitly specified for the first time in the failed Treaty establishing a Constitution for Europe, and carried over into its replacement, the Treaty of Lisbon.