Sir Keir Starmer will leave 10 Downing Street as the shortest-serving Labour prime minister in history, with his period in office ranking as one of the briefest in modern times.
His resignation on Monday comes on the 717th day of his premiership, outlasting his two immediate Conservative predecessors: Rishi Sunak (619 days from October 2022 to July 2024) and Liz Truss (49 days from September to October 2022).
Sir Keir also spent longer in office than two other post-1900 prime ministers: Conservatives Andrew Bonar Law (211 days from October 1922 to May 1923) and Anthony Eden (645 days from April 1955 to January 1957).
However, Sir Keir will not have a chance to move any further up the rankings.
He would need to remain in office until November 5 of this year to climb another place up the list, at which point he would overtake Liberal prime minister Henry Campbell-Bannerman, who served 852 days in office from 1905 to 1908.
Sir Keir has already indicated he will stand down by September, which is the latest possible date for the conclusion of a leadership contest.
Had he clung on as prime minister until at least May 21 2027, he would have spent longer in office than Gordon Brown (1,049 days from June 2007 to May 2010).
Instead he will leave Downing Street as his party’s shortest-serving premier in history, behind all six previous Labour prime ministers.
Tony Blair remains Labour’s longest-serving PM, clocking up 3,708 days from May 1997 to June 2007.
In second place is Harold Wilson, who served two non-consecutive periods in office, October 1964 to June 1970 and March 1974 to April 1976, which together totalled 2,835 days.
Ramsay MacDonald also spent two non-consecutive periods as prime minister, from January to November 1924 and June 1929 to June 1935, adding up to 2,480 days – though for the period from 1931 to 1935 he was a member of the short-lived National Labour party, having been expelled from the official Labour party after forming a coalition government.
Clement Attlee was Labour prime minister continuously for 2,283 days from July 1945 to October 1951, while Jim Callaghan clocked up 1,124 days from April 1976 to May 1979, just ahead of Gordon Brown’s total of 1,049.
