According to the Maastricht Treaty, each current member state and the European Parliament must agree to any enlargement.
The 2004 enlargement of the European Union was the largest single expansion of the European Union (EU), in terms of territory, number of states, and population to date; however, it was not the largest in terms of gross domestic product. The simultaneous accessions concerned the following countries (sometimes referred to as the "A10" countries): Cyprus, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia, and Slovenia.
European communist countries had a looser economic grouping with the USSR known as Comecon.
To the south there was a non-aligned communist federated country - Yugoslavia.
This term is also used to refer to the intensification of co-operation between EU member states as national governments allow for the gradual harmonisation of national laws.
To join the European Union, a state needs to fulfill economic and political conditions called the Copenhagen criteria (after the Copenhagen summit in June 1993), which require a stable democratic government that respects the rule of law, and its corresponding freedoms and institutions.
Welcome to the Maynooth Centre for European and Eurasian Studies.
Our outreach activities are designed to connect the Centre with the community and help provide knowledge and information about Europe to the widest possible audience.
The Phare strategy was launched soon after to adapt more the structure of the Central and Eastern European countries (Pays d'Europe Centrale et Orientale (PECO)) to the European Economic Community.
The Daylight Saving Time (DST) period in Europe runs from Coordinated Universal Time (UTC) on the last Sunday of March to UTC on the last Sunday of October every year.
This is the inevitable consequence of opening our borders when Britain is creating more jobs than the rest of the EU put together.
Last week, Lithuanian Prime Minister Algirdas Butkevičius spoke publicly about the huge numbers of his population to have moved to Britain in recent years, after meeting Mr Cameron at a conference in Finland.