Prime minister weighs early prisoner release policy amid overcrowding crisis

The prime minister has declined to commit to changing England and Wales’s early prisoner release scheme, saying he wants to examine it in detail “before we go further forward”. The move keeps pressure on a policy introduced last year to ease a severe prison overcrowding crisis, while ministers face fresh warnings about the risk to public safety.

The scheme, known as SDS40, was announced by the Lord Chancellor on 12 July 2024 as emergency action to stop prisons running out of space. It allowed some prisoners serving standard determinate sentences to be released after serving 40% of their term instead of the usual 50%, with releases beginning on 10 September 2024 for Tranche 1 and on 22 October 2024 for Tranche 2.

Official figures now show the scale of the policy: almost 40,000 prisoners in England and Wales have been released early under SDS40 since September 2024. The numbers underline how quickly an emergency measure designed to avert a summer prison disaster became a central part of the government’s response to long-running pressure across the jail estate.

That response has drawn warnings from senior police and security leaders. A letter to the Ministry of Justice raised concerns about the government’s proposals, with the head of the Metropolitan Police and MI5 chief Ken McCallum among those cautioning that early release could create public-safety risks if it is not properly funded and managed. The probation chief has also questioned whether there is enough time to implement the plan safely.

The debate is now widening beyond the emergency scheme itself. Victims’ Support has said victims of all types of crime should be able to find out if an offender is being released early, arguing that people affected by crime are left in the dark when rules are too narrow. At the same time, Andy Burnham has been exploring whether child sex offenders should be barred from early release, adding a tougher carve-out to the current policy.

The wider sentencing review being considered by ministers is being shaped by the same tradeoff that led to SDS40 in the first place: how to avoid a collapse in prison capacity without weakening protection for the public. Government review papers and the Independent Sentencing Review point to alternatives to custody, progression from custody to community, and steps to prevent prisons from running out of space again. If ministers slow or reverse SDS40, they will have to find another way to relieve overcrowding without reopening the crisis the policy was designed to solve.