Andy Burnham’s recent ascension as prime minister in July 2026, following Keir Starmer’s resignation amid Labour’s poor local election results and internal party pressure, anchors trader expectations around a total of two UK prime ministers by the end of 2027. Burnham secured the leadership unopposed with broad parliamentary backing and now heads a government with a sizable Commons majority that runs until the next scheduled general election in 2029. This stability, combined with the short timeframe remaining before 2028, makes an additional leadership contest or snap election appear unlikely to most traders. A third prime minister would require either rapid erosion of Burnham’s support or unforeseen external shocks capable of forcing an early vote, scenarios priced at just 14.5 percent. The 1.5 percent tail for four or more reflects even lower odds of sustained volatility.