Euro moments: 'Vote yes - clearly and unmistakably'
7 May 2014 Last updated at 09:31 BST
"This issue has hung around for far too long," says Foreign Secretary James Callaghan as he urges fellow Britons to go out and vote.
He said Britain's prosperity - as well as peace and security - would be protected in the common market, making the government's case for a "Yes" vote ahead of the referendum on the UK's membership of the European Economic Community in 1975.
Just over 67% of voters heeded their message and backed the campaign to stay in the EEC, or Common Market, despite several ministers in the Labour government having come out in favour of British withdrawal.
The result was later hailed by Prime Minister Harold Wilson as a "historic decision".
The Conservative leadership also wanted a "Yes" vote. Margaret Thatcher, elected Tory leader earlier that year, said the "Yes" vote would not have happened without the opposition's support.
Clip taken from The Pro-EEC Campaign's Referendum Campaign Broadcast, first broadcast 3 June 1975