Fundamental to the EU is the idea that many areas of policy can be more effective if established at a European rather than a national level.

Policy areas include removing trade barriers to boost growth and jobs; improving our environment; and fighting international crime and illegal immigration.

In many cases these policies must then be turned into law, binding across borders. The EU has created a framework of processes and institutions to do this.

The framework has evolved through a series of intergovernmental conferences (IGCs) and treaties that must be ratified by each member state.

Above all European laws underpin the single European market, designed to create uniform trading conditions and the free movement of goods, persons, services and capital between all EU member states.

The European Court oversees implementation and interpretation of European laws.

Overall the EU has proved remarkably successful in balancing the individual interests of member states against the benefits of pan-European collaboration.