Herbert Stanley Morrison, Baron Morrison of Lambeth, was a British politician who held a variety of senior positions in the Cabinet as a member of the Labour Party. During the inter-war period, he was Minister of Transport during the Second MacDonald ministry, then after losing his parliamentary seat in the 1931 general election, he became Leader of the London County Council in the 1930s. After returning to the Commons, he was defeated by Clement Attlee in the 1935 Labour Party leadership election but later acted as Home Secretary in the wartime coalition.

The Labour Party is a political party in the United Kingdom that has been described as an alliance of social democrats, democratic socialists, and trade unionists. The Labour Party sits on the centre-left of the political spectrum. In all general elections since 1922, Labour has been either the governing party or the Official Opposition. There have been six Labour prime ministers and thirteen Labour ministries. Since the 2010 general election, it has been the second-largest UK political party by the number of votes cast, behind the Conservative Party and ahead of the Liberal Democrats. The party holds the annual Labour Party Conference.