Labour's commanding Commons majority, secured in the 2024 general election and still intact as of mid-June 2026, remains the decisive structural barrier to any successful no-confidence motion. Despite widespread internal dissent—including multiple ministerial resignations, over 90 Labour MPs urging Starmer to set a departure timetable after heavy May local and devolved election losses, and opposition rhetoric from the Conservatives and SNP—the arithmetic makes passage improbable without dozens of Labour defections. Party rules channel leadership pressure through internal challenges rather than automatic Commons votes, and no procedural trigger or cross-party agreement has emerged to force a binding motion before the June 30 deadline. Traders therefore assign overwhelming probability to "No," reflecting the gap between media speculation over Starmer's authority and the institutional requirements for removing a sitting government.