Liz Truss has become the shortest-serving prime minister in history, announcing her resignation after just 44 days in office. Speaking outside No 10 on Thursday afternoon, she admitted she could no longer deliver on the mandate she was elected with last month. Ms Truss's premiership is the shortest by some margin, with George Canning previously holding the unwanted title.He died 118 days after taking office in 1827. Of more modern prime ministers, Alec Douglas-Home also had a short premiership, lasting 364 days in the role from 1963-64.