No standing prison-capacity mechanism: crisis managed by ad hoc emergency releases

The prison estate holds more than 87,000 people, roughly 25 per cent above certified normal capacity, and the Public Accounts Committee warned in early 2026 that places could run out within months. The NAO found in December 2024 that only a third of the promised 20,000 new places had been delivered, with costs up 80 per cent and a 12,400-place shortfall projected by 2027. Governments have improvised each time: Operation Safeguard put prisoners in police cells, Operation Early Dawn delayed magistrates' hearings, SDS40 released people early, and the Sentencing Act 2026 brings an earned-progression model from autumn 2026. The missing thing is an institution. No independent body forecasts demand against capacity, scores sentencing legislation for capacity impact before enactment, or triggers a codified contingency ladder, an omission the Institute for Government flagged in the Gauke implementation plan. The Independent Review of Prison Capacity documented the failure in August 2025 and created no standing mechanism.

Every emergency measure so far was announced days before capacity ran out, shifting risk onto police cells, courts and probation without notice. Sentencing policy is made without seeing capacity, then corrected by mass early release. That correction costs sentence integrity and victim confidence, and it wrecks rehabilitation planning.

A statutory prison capacity mechanism. An independent advisory body on the OBR model would publish demand forecasts and mandatory capacity impact assessments for all sentencing legislation. Government would make an annual capacity statement to Parliament, and a codified contingency protocol would replace the ad hoc operations. The next criminal justice bill could carry all of it.

// State-led: Instrument: next criminal justice bill creating OBR-style capacity body, mandatory impact assessments and codified contingency protocol.

The estate sits far over capacity with places projected to run out within months, and no standing body forecasts demand or scores sentencing laws before they pass.