BUSINESS AND ECONOMY
The European Parliament (EP) scrutinises, amends and passes legislation on the internal market.
It has voted to remove barriers to free movement of goods, services, people and capital, and aims to bring about more liberalisation of markets for transport, telecommunications, electricity, gas, and postal services.
The EP has passed legislation on the harmonisation of company law, modernisation of public procurement and protection of intellectual property. Technical specifications for goods have been harmonised.
The EU budget cannot be passed without the approval of the EP, so it has power over the allocation of funds to priorities or programmes supporting projects in member states, for example the Regional Development Fund.
Under the Lisbon Treaty, MEPs have increased powers over the application of structural funds, which is money given to poorer regions of the EU.
Finally, the EP can now pass specific laws on monetary policy with regards to measures necessary for the use of the Euro.
CULTURE, SCIENCE AND SPORT
The EP, directly representing EU citizens, has equal powers with the Council, representing national governments, when adopting legislation in the field of culture. But the EU's actions are limited and it can only support or complement national policies.
MEPs can legislate on EU-wide proposals on intellectual property regulations, sport and tourism.
Following ratification of the Lisbon Treaty, the European Parliament can now legislate on the EU's space policy.
DEFENCE AND FOREIGN AFFAIRS
The EP has no formal role in discussions on defence policies or external relations, since decisions are taken elsewhere - primarily in the Council of Ministers.
But it can and does frequently debate these matters and voice opinions on them.
Member states have full responsibility for the organisation and content of their education and training systems.
The EU can only promote co-operation between member states or support their actions; its goals have been so far to promote cross-border mobility of students and teachers, for example via exchange programmes such as Erasmus.
The EP has passed legislation binding on members states which allows better recognition of qualifications from school-leavers' diplomas, vocational training certificates and academic degrees across national borders.
The EP can pass laws on environmental matters which are then binding on member states, so long as they have also been agreed with ministers from national governments at the Council.
But there is nothing stopping member states from agreeing measures that go beyond the minimum standards set by the EU.
EU-wide policy aims to protect the soil, water, climate, air, flora and fauna, and promote better use of natural resources.
The European Parliament has recently adopted rules on pesticides, targets for recycling, rules on hazardous substances, protecting groundwater, and reducing CO2 emissions of cars.
FARMING AND FISHERIES
Under the Lisbon Treaty, the European Parliament now has full legislative powers on the controversial areas of the common agricultural and fisheries policies.
These were previously the sole preserve of the Council of Ministers, with the EP only having a consultative role.
Health services and hospitals are legally the sole responsibility of member states.
But the EU can coordinate common actions taken to protect human health and prevent illnesses and diseases.
The EP has joint powers with the Council to adopt a range of legislation which affects health policy in member states, such as the recognition of health professional qualifications between countries, the working time directive or the use of mercury in instruments.
It also frequently legislates on matters regarding consumer protection and food safety - policies which are shared between member states and EU institutions.
HOUSING AND PLANNING
The EU has no mandate for housing and planning, which remain solely national, regional and local competences.
However, legislation passed by the EP can have an impact in these areas, e.g. public procurement processes, harmonised European standard for construction products, energy efficiency requirements for buildings, environmental impact assessments for planning authorities.
JUSTICE AND HOME AFFAIRS
MEPs have increasingly been given more powers over policing and judicial co-operation.
The EP is a co-legislator with the Council of Ministers on some aspects of asylum (such as conditions for the reception of applicants), legal immigration (such as rules on entry and residence conditions) and the powers of Europol and Eurojust.
The European Parliament can also legislate on border checks, human trafficking laws, and minimum rules on criminal sanctions on cross-border serious crimes.
The UK has opted out from the Schengen agreements, which removed border controls between member states, as well as some non-EU countries such as Norway.
Local governments are affected by a range of EU legislation adopted with the consent of the European parliament: public procurement rules, EU environmental laws (waste, air quality or noise directives), and energy efficiency of buildings.
This remains the sole responsibility of domestic institutions.
The European Parliament has helped develop a common policy for rail, road, inland waterway, maritime and air transport across EU member states.
The EP supports more competition in the transport markets and harmonization of infrastructure between member states.
Safety standards have also been harmonized.
MEPs have passed legislation on air passengers' rights, driving time in the road transport sector, ship dismantling, prevention of marine pollution, and a standard EU model for driving licences.