Edward Heath of the Conservative Party formed the Heath ministry and was appointed Prime Minister of the United Kingdom by Queen Elizabeth II on 19 June 1970, following the 18 June general election. Heath's ministry ended after the February 1974 general election, which produced a hung parliament, leading to the formation of a minority government by Harold Wilson of the Labour Party.

Harold Wilson of the Labour Party would form his Second Shadow Cabinet, as Leader of Her Majesty's Most Loyal Opposition, after losing the 1970 general election to Conservative Edward Heath. He would retain leadership of the Opposition for the length of the Heath Ministry, from 1970 − 1974. In February 1974, his party would narrowly win an election. Wilson was then forced to form a minority government, which would only last until another election in October of that year. Following that election, Wilson would form a majority government.