Prime Minister of the United Kingdom century as a convention of the constitution, the position of Leader of the Opposition was given statutory recognition in 1937 by the Ministers of the Crown Act. British Prime Ministers have never been elected directly by the public. A Prime Minister need not be a party leader; David Lloyd George was not a party leader during his service as prime Minister during World War I, and neither was Ramsay MacDonald from 1931 to 1935. Prime Ministers have taken office because they were members of either the Commons or Lords, and either inherited a majority in the Commons or won more
Timeline of Prime Ministers of the United Kingdom political career in the UK Parliament and typically serves many years in the House of Commons before becoming Prime Minister, and in some cases for many years afterwards. Since the Marquess of Salisbury in 1895, all time in parliamentary service before being Prime Minister has been in the House of Commons, apart from Sir Alec Douglas-Home's period as a member of the Government while in the House of Lords (1951–63; though he was previously the elected member for Lanark, 1931-1945). After becoming Prime Minister, Douglas-Home returned to the Commons by winning a by-election on the recess death of MP Gilmour