Keir Starmer's expected resignation date as Prime Minister has been brought forward by 8 days to 13 September 2026, according to the latest shifts in Polymarket betting markets. This suggests the Labour leader's position is under increasing pressure.
The new 13 September 2026 resignation date is now implied with ~86% probability, up from the previous 21 September 2026 timeframe. Starmer's allies have not yet commented on the change.