Chancellor John Healey’s first Budget on 28 October 2026 arrives amid elevated UK gilt yields at multi-decade highs and slower growth, tightening the government’s fiscal headroom against its rules of balancing day-to-day spending and reducing debt-to-GDP by parliament’s end. Labour’s manifesto commitments rule out rate rises on income tax, National Insurance, and VAT, shifting focus to capital gains, inheritance tax, property levies, welfare reforms, and business rates adjustments. Recent Iran-related pressures have lifted borrowing costs, while the Office for Budget Responsibility’s updated forecasts will anchor market-implied odds on specific measures. Traders are watching the 28 September Labour conference speech for signals on first-time buyer schemes and regional funding before the OBR release.