European Union law is the system of laws operating within the member states of the European Union. The EU has political institutions and social and economic policies. According to its Court of Justice, the EU represents "a new legal order of international law". The EU's legal foundations are the Treaty on European Union and the Treaty on the Functioning of the European Union, unanimously agreed by the governments of 28 member states. New states may join the EU, if they agree to operate by the rules of the organisation, and existing members may leave according to their "own constitutional requirements". Citizens are able to vote directly in elections to the Parliament, while their national governments operate on behalf of them in the Council of the European Union and the European Council. The Commission is the executive branch. The Council of the European Union represents member state governments, while the Court of Justice is meant to uphold the rule of law and human rights. As the Court of Justice said, the EU is "not merely an economic union" but is intended to "ensure social progress and seek the constant improvement of the living and working conditions of their peoples".