Recent parliamentary by-elections in the UK have been triggered primarily by MP resignations, including Keir Starmer stepping down from Holborn and St Pancras in September 2026 to focus on international affairs and Nigel Farage’s earlier move in Clacton amid party finance scrutiny. No further Westminster contests currently have confirmed polling dates, though vacancies can arise quickly from health issues, moves to other offices such as the Scottish Parliament, or strategic decisions. Local council by-elections occur more frequently due to routine resignations and continue through October and November 2026 across multiple authorities. Trader assessments of the next trigger typically weigh public statements from sitting MPs, party conference dynamics, and any emerging personal or professional pressures that could prompt an early vacancy before the next general election.