It provided for a single commission and a single council of the then three European Communities. The Merger Treaty entered into force on July 1, 1967. In 1973 the European Community (EC) was strengthened with the additions of the United Kingdom, Ireland and Denmark. The United Kingdom had previously applied for membership but Charles De Gaulle did not want the United Kingdom to be part of the European Community so membership was denied. Because Ireland and Denmark had significant economic ties to the United Kingdom they would not join the European Community unless the United Kingdom was granted membership.
In 1979 the European Parliament was elected, for the first time, by direct universal suffrage and the European Monetary System (EMS) became operative. Two years later in 1981 Greece becomes the tenth member state and in 1986 Spain and Portugal became the 11th and 12th member states of the European Community. .
In 1985 the program to complete the Single Market by 1992 was launched. The single market would give four basic freedoms - the free movement of goods, persons, services and capital in the EU. The Single Market legislation also increased the power of the European Parliament. The Single European Act (SEA) in 1987 introduced majority voting on. And then in 1989 The Madrid European Council launched the plan for achievement of Economic and Monetary Union. .
The two parallel intergovernmental conferences produce the Treaty on European Union (Maastricht) which EU leaders approve at the Maastricht European Council. In 1992 the Treaty on European Union was signed in Maastricht and was sent to member states for ratification. The first referendum in Denmark rejects the Treaty. Finally in May 1993, a second Danish referendum ratified the Maastricht Treaty, which took effect in November. .
To strengthen integration, the Maastricht Treaty on European Union cleared the way for the completion of the Economic and Monetary Union (EMU), involving the introduction of a single currency no later than 1999 and a European Central Bank.
