The Labour Party manifesto for the 1974 general election promised the public a referendum to decide whether to remain in the European Community (or Common Market) which the UK had officially joined the year before under the Conservative government of Edward Heath. It was the first national referendum ever to be held throughout the whole of the United Kingdom and Labour promised to honour the verdict either way with Prime Minister Harold Wilson supportive of the Yes campaign. A large turnout (64% of the electorate) expressed support for EC membership with 67.23% in favour of remaining members. In Wilson's subsequent speech he said it had been 'a free democratic campaign conducted constructively and without rancour. It means that fourteen years of national argument are over. It means that all those who have had reservations about Britain's commitment should now join wholeheartedly with our partners in Europe...'.
In 2016 the Conservative government sparked another referendum with an even larger turnout of voters (72% of the electorate) but a considerably narrower margin between the No (Leave) and Yes (Remain) votes (51.89% vs. 48.11% respectively). This led to prolonged national argument once again and the UK's withdrawal from the European Union on 31 January 2020.