<P> The United Kingdom European Communities membership referendum , also known as the Referendum on the European Community ( Common Market ) , the Common Market referendum and EEC membership referendum took place on 5 June 1975 in the United Kingdom to gauge support for the country 's continued membership of the European Communities ( EC ) -- often known at the time as the `` European Community '' and the `` Common Market '' which it had entered on 1 January 1973 under the Conservative government of Edward Heath under the provisions of the Referendum Act 1975 . Labour 's manifesto for the October 1974 general election had promised that the people would decide `` through the ballot box '' whether to remain in the EC . </P>
<P> The United Kingdom European Communities membership referendum , also known as the Referendum on the European Community ( Common Market ) , the Common Market referendum and EEC membership referendum took place on 5 June 1975 in the United Kingdom to gauge support for the country 's continued membership of the European Communities ( EC ) -- often known at the time as the `` European Community '' and the `` Common Market '' which it had entered on 1 January 1973 under the Conservative government of Edward Heath under the provisions of the Referendum Act 1975 . Labour 's manifesto for the October 1974 general election had promised that the people would decide `` through the ballot box '' whether to remain in the EC . </P>
when did the uk become part of eu
when did the uk become part of eu
on 1 January 1973
on 1 January 1973