The Prime Minister's expected resignation date has been brought forward by 3 days, from 28 September 2026 to 26 September 2026, according to the latest Polymarket betting data.
This shift in the implied resignation timeline comes as the political landscape continues to evolve around Keir Starmer's leadership of the Labour Party. The new date of 26 September 2026 is now being priced at ~86% probability of Starmer stepping down as PM by that point.