Sir Keir Starmer made the leap from Leader of the Opposition to Prime Minister in only four years, one of just a handful of politicians to have done so since 1945. Yet the landslide majority that Labour secured under him in July 2024 has been described as 'loveless' and his first months in Downing Street were overshadowed by rows and controversies, turning what should have been a political honeymoon into a period of sustained turbulence. In this fully revised and updated edition of his 2021 biography, Michael Ashcroft traces how Starmer went from schoolboy socialist to radical lawyer and Director of Public Prosecutions before – aged fifty-two – becoming an MP, then Labour leader and ultimately the occupant of No. 10. Revealing previously unknown details which help to explain what makes Starmer tick, this careful examination of Britain's first Labour Prime Minister for fourteen years offers voters the chance to assess his character and his political instincts. Having turned his party into an election-winning machine, his goal is to transform Britain into one of the most progressive states in the world. Does he have what it takes to succeed?