Replacing a leader is difficult, as Jeremy Corbyn proved – but MPs can apply pressure, publicly or privately

Many Labour MPs believe Keir Starmer will not survive as Labour leader for long enough to fight the next election. What they cannot agree on, however – even after a disastrous set of results in this week’s elections – is how his departure might come about.

The Labour rulebook makes it notoriously difficult to unseat a party leader: none has been formally ejected in the postwar period, though some, including Tony Blair, have resigned under pressure from their own MPs.

A curveball was thrown into the mix on Saturday when the backbencher Catherine West launched a leadership challenge.

West, the MP for Hornsey and Friern Barnet and a junior Foreign Office minister until she was sacked in the reshuffle last year, announced that unless a cabinet minister came forward to challenge Starmer for the leadership by Monday morning, she would do it herself.