The UK’s unwritten constitution: There are no real rules

Mark Leftly | 23rd June 2026 | Comment

The timing and in what circumstances a leader should stay or go are in flux, argues Mark Leftly.

Sir Keir Starmer is the 43rd longest serving prime minister in our country’s history. If a brave enough soul challenges Andy Burnham to become the next Labour leader, Sir Keir could still leapfrog The Earl of Aberdeen – a mid-19th century, landowning Peelite – into 42nd place. Assuming a coronation or the very possible failure of another candidate to get the support of the 81 MPs needed to stand, however, Sir Keir will stay 43rd. He will have been in Downing Street for just two years and a few days in change. That’s one place and a few months ahead of Sir Anthony Eden, whose premiership was considered extremely short when he quit on grounds of ill health in 1957, shortly after the Suez crisis. We’ve only had 58 prime ministers, yet five of the past six rank well outside the top 30 for length of time in office. Even David Cameron, who now appears to be a beacon of longevity at a little more than six years, fails to crack the top 20. There is little doubt that each of those ...

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