The expected resignation date of Prime Minister Keir Starmer has been brought forward by 2 days, from 16 September 2026 to 15 September 2026, according to the latest Polymarket data.
The change in the implied resignation date comes as the probability of Starmer resigning by 15 September 2026 has increased to ~86%, up from ~84% previously. Traders on Polymarket appear to be increasingly confident the PM will step down by the middle of next month.