The participation of Spain in the European Union, begun in 1986, and the gradual increase in the powers that successive Community Treaties have been attributing to the European institutions has a direct effect on the internal political organization and on the powers that the 1978 Constitution attributed to the Autonomous Communities. These effects are particularly relevant in the area of exclusive Community competences, and in particular in terms of competition policy; but they are also intense in the area of shared competences, such as in agriculture and fisheries, the environment, cohesion policy, social policy, consumer protection, transport or energy.

This situation has been resolved at Spanish level through the establishment of a system of cooperation that makes possible the autonomous participation in the bodies of the institutions in which the Community acts are elaborated and adopted.