By July 21, 2026, neither Andy Burnham will publicly declare candidacy in a Labour leadership contest nor Keir Starmer will formally announce his resignation as party leader — the current Labour leadership equilibrium will be maintained throughout this period.

The base rate for a mid-Parliament UK opposition leader formally triggering a succession process within any given 3-month window is approximately 7% — structurally rare. Adjustment factors: elevated dissatisfaction signals and Burnham’s elevated media profile push the YES probability upward by roughly 8 percentage points to ~15%. Four-framework convergence on NO then applies a strong downward adjustment. The institutionalist framework carries highest weight (0.40) because it provides the most mechanistically specific account: Labour’s post-2016 rules impose discrete supermajority thresholds, not continuous gradients, meaning accumulated pressure does not smoothly translate into formal trigger — there is no threshold-crossing until there is. The Keynesian analysis (0.30 weight) adds self-reinforcing dynamics: liquidity preference and the paradox of thrift in political capital produce collective stasis even when individual actors privately desire change — each challenger’s rational conservation destroys the aggregate investment climate. Marxist apparatus-resistance (0.15) and Austrian option-value logic (0.15) reinforce the NO direction but are assigned lower weights because both acknowledge significant residual uncertainty about contingent shocks that their frameworks cannot predict. Synthesizing: P(YES by July 21) ≈ 0.15, adjusted upward slightly to 0.15 given the UK political environment’s current volatility. Final confidence in NO: 0.85. Confidence in confidence is medium because exogenous shock events — the one mechanism all four frameworks identify as the primary YES pathway — are structurally unforecastable by construction.