The new government has pledged to ‘get a grip’ on the prison population crisis amid growing speculation that prisoners will be released earlier in their sentence.

According to media reports, the government is considering lowering the automatic release point from the current 50% of time served to 40%. An announcement is expected by the end of this week.

Lowering the automatic release point to 40% was one of the emergency measures proposed in the Centre for Justice Innovation’s post-election criminal justice plan – a plan backed by former Labour lord chancellor Lord Falconer, a patron of the justice reform charity.

Writing in The Telegraph today, former Home Office minister Robert Jenrick MP - who is being tipped to enter the race to become the next Conservative Party leader - said letting out thousands of prisoners 40% of the way through their sentence ‘risks triggering a crime wave of rapes, assaults and robberies in the very near future’. Jenrick suggested Labour could, instead, deport foreign criminals and ban them from re-entering the UK, or deliver rapid deployment cells.

However, in a letter to party leaders ahead of the election, the Prison Governors Association, which represents over 95% of prison governors, called for an immediate change in legislation that would see prisoners routinely released from custody at the 40% mark. The association said it would be far easier to release prisoners earlier from custody ‘than to be in a position where the police and courts have nowhere to send even the most serious offenders.’

The association added: ‘There may be other options which help, but these will not have the immediate impact required. Without a significant reduction in the prison population now, the criminal justice system will fail, and the public will be put at risk.’

An uncrowded prison system should have no more than about 78,000 people in custody, the association said. The prison population currently stands at more than 87,000.

A government spokesperson said: ‘The prison system is in crisis – with record numbers of offenders behind bars. This is putting significant pressure on the whole justice system and turning prisons into a breeding ground for more crime. We will get a grip of the situation so we can lock up the most dangerous offenders, protect the public and make our prisons safer for hard-working staff.’