Recent leadership instability, including Keir Starmer's resignation amid sharply negative approval ratings and internal Labour Party pressure, has already produced a transition to Andy Burnham as prime minister in July 2026. With Labour holding a large parliamentary majority from the 2024 election and the next general election not due until around 2029, traders assign an 85.5% probability to exactly two prime ministers serving by the end of 2027. This reflects broad expectations of continuity under Burnham, tempered by the modest 14.5% chance of further internal party challenges or unforeseen events prompting an additional change. The low 1.3% odds for four or more underscore how rare rapid successive turnovers would be under current conditions.