Enoch Powell

A cross-party campaign and a formal switch. Powell stood down as a Conservative before the February 1974 election and urged voters to back Labour because it offered a referendum on Common Market membership; some analysts think he swung enough votes to change the result. In 1975 he campaigned for a No vote alongside Tony Benn and Michael Foot. He then sat as an Ulster Unionist MP for South Down until 1987. His 1968 'Rivers of Blood' speech remains the dominant part of his legacy.