Such competence is recognised in the EU Treaties which, since the foundation of the European Economic Community, also foresee a role for the EU to support and complement the activities of the Member States.
Selline pädevus on sätestatud ELi aluslepingutes, millega on juba Euroopa Majandusühenduse loomisest saati ette nähtud, et ELi roll on toetada ja täiendada liikmesriikide meetmeid.