The appointment of the prime minister by the monarch

Conventions can Evolve. 

While the last time a British monarch used their prerogative powers to appoint a favoured prime minister was nearly two centuries ago in 1834, when William IV dismissed the Whig administration and appointed Lord Melbourne, the king or queen is still constitutionally responsible for appointing UK prime ministers. Queen Elizabeth II appointed a total of 15 prime ministers during her reign, including the shortest-serving prime minister, Liz Truss. Truss tendered her resignation to the Queen’s successor, King Charles, just 44 days later. The king in turn appointed Rishi Sunak in October 2022. The convention of royal appointment is evolving, seen as being progressively more dependent on clear advice offered by the prime minister as to who should be appointed next. Not only did the (now annulled) Fixedterm Parliaments Act pose a serious problem, potentially allowing for the office of prime minister to be vacant for lengthy periods of time, but the growing convention for prime ministers to prolong their departures to allow a clear successor to emerge has become increasingly expected