President Blair & PM Cameron

The European Union can only exercise competence's that the Member States have conferred on it in the Treaties. The EU, therefore, is only competent to act within the scope of the powers allocated to it by its Member States.

In policy areas that are within the scope of the Union's exclusive competence, Member States may not implement any measures that might jeopardise the efficient attainment of Union-level objectives in those areas. These include common Trade, Agriculture, Fish , Justice and Home Affairs, Employment, Social Policy, Health and Consumer Affairs, Competitiveness, Transport, Telecommunications and Energy, Environment and Education, Youth and Culture.