James Callaghan became Leader of the Opposition on 4 May 1979 after losing the 1979 election and remained in that office until Michael Foot was elected Leader of the Labour Party on 2 October 1980. Callaghan named his Shadow Cabinet in June 1979, with Foot (the Deputy Leader) and the 12 elected members of the Shadow Cabinet assigned portfolios on 14 June^[1] and further appointments made on 18 June.^[2] From the opening of Parliament until that date, Callaghan's Cabinet, with a few exceptions, stayed on to shadow their former positions.

Callaghan assigned portfolios in June 1979 to the Deputy Leader and the 12 winners in the 1979 Shadow Cabinet elections.^{[n 1]}