A Bad Idea Forty Years On

Ted Heath's worst moment:

Britain was widely referred to – not least by Britons themselves – as ‘the sick man of Europe’, and small wonder. The country which had, in recent enough memory, stood alone against the Nazi-Soviet domination of Europe, was losing the Cod War to Iceland.
It was in these miserable circumstances that, on 1 January 1973, the United Kingdom formally became a member of the European Economic Community.