Brussels and the European Union a provisional seat, though with the Common Assembly in Strasbourg as that was the only city with a large enough hemicycle (the one used by the Council of Europe). This agreement was temporary, and plans were set to relocate the institutions to Saarbrücken which would serve as a "European District", but this did not occur. The 1957 Treaties of Rome established two new communities, the European Economic Community (EEC) and the European Atomic Energy Community (Euratom). These shared the Assembly and Court of the ECSC but created two new sets of Councils and Commissions (equivalent to the ECSC's High Authority).
2016 United Kingdom European Union membership referendum or Euratom) and European Economic Community (EEC) in 1957. The EEC, the more ambitious of the three, came to be known as the "Common Market". The UK first applied to join them in 1961, but this was vetoed by France. A later application was successful, and the UK joined in 1973; two years later, the first ever national referendum on continuing membership resulted in 67.2% approval. Political integration gained greater focus when the Maastricht Treaty established the European Union (EU) in 1993, which incorporated (and after the Treaty of Lisbon, succeeded) the European Communities. Prior to the 2010 general election,