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.

The Leader of His Majesty's Most Loyal Opposition, more commonly referred to as the Leader of the Opposition, is the person who leads the Official Opposition in the United Kingdom. The position is seen as the shadow head of government of the United Kingdom and thus the shadow prime minister of the United Kingdom.