Five by-elections have already occurred in 2026, including those in Gorton and Denton, Makerfield, Aberdeen South, Arbroath and Broughty Ferry, and Clacton, driven by resignations tied to health issues, leadership maneuvers, and strategic decisions such as Nigel Farage's temporary departure. With roughly four months remaining, trader consensus splits closely between five and six total contests, reflecting historical patterns of vacancies from deaths, retirements, or party pressures alongside the low but present chance of one additional trigger before year-end. Further MP announcements could quickly shift probabilities, while a quiet period would favor the lower outcome.