Andy Burnham has said he is “increasingly confident” that the government can create enough additional prison space to prevent the killers of PC Andrew Harper from being released early, as ministers come under mounting pressure to find a solution.

The prime minister has asked Justice Secretary Alex Norris to fast-track a plan designed to create more capacity across the prison estate, potentially allowing fewer offenders to be released early while keeping some of the most serious criminals behind bars.

The announcement follows weeks of anger over plans that could see Jessie Cole and Albert Bowers released next January.

The pair were convicted of manslaughter over the death of PC Harper, who was killed while responding to a quad bike theft in Berkshire in 2019.

Under the current sentencing changes, Cole and Bowers are expected to become eligible for release after serving half of their 13-year sentences.

Their potential release has caused widespread outrage, particularly among Harper’s family and police officers.

Harper’s widow, Lissie Harper, has previously campaigned for the two men to remain in prison, while his mother, Debbie Adlam, has repeatedly called on the government to ensure that her son’s killers serve the sentences they were given.

The government had already announced exemptions from the early-release scheme for prisoners convicted of rape, serious child sex offences and grooming offences.

However, Cole and Bowers were not included in those exemptions because their convictions were for manslaughter rather than murder.

That left ministers facing a difficult legal and practical problem.

The government could not simply exclude the two men from the scheme without potentially affecting other prisoners convicted of manslaughter.

At the same time, creating an exemption so narrowly targeted at Harper’s killers could face legal challenges.

Downing Street had previously said that the manslaughter of an emergency worker was not a standalone offence, meaning it was not possible simply to remove one or two individual offenders from a wider category.

Now, Burnham has indicated that the government believes it may be possible to solve the problem without dramatically expanding the list of offences excluded from early release.

In a statement, he said he understood the strength of public concern surrounding Harper’s killers.

“I understand the depth of public concern about the potential early release of those involved with the killing of PC Andrew Harper – and I share it,” he said.

He also acknowledged the anguish experienced by Harper’s family and other victims whose attackers could potentially serve less time in prison than originally expected.

“It is incumbent on me as Prime Minister to do everything within my power to minimise that possibility,” Burnham said.

“And I am determined to do so.”

The prime minister said he had spent recent days examining the issue and considering advice on what could be done.

He rejected the idea that the current situation meant no further action was possible.

“I have been pushing for further progress. I have not accepted that it is impossible to do more,” he said.

Burnham has now asked Norris to present a plan to Parliament in September.

The proposed strategy would focus on creating additional “headroom” within prisons rather than simply excluding more categories of offenders from the early-release scheme.

Three possible measures have been identified.

The first is increasing the rate at which foreign national offenders are removed from the prison estate and returned to their countries of origin.

The second involves finding an early resolution to the long-running issue surrounding imprisonment for public protection, or IPP, sentences.

The third would involve making greater use of the entire prison estate, including potentially using parts of the female prison estate for male offenders.

Burnham said these measures could allow the government to reduce the overall number of people released early.

Crucially, he suggested they could also make it possible to prevent the early release of prisoners convicted of the most serious offences.

“I am increasingly confident that a more focused approach along these lines will allow us to reduce the number of people released early and, in the case of the most serious offenders like those convicted of the killing of PC Harper, prevent their early release altogether,” he said.

His comments were reinforced by Angela Rayner, who said a solution had already been identified.

Speaking to LBC, the housing secretary said Norris would return to Parliament in September to set out the government’s plans.

Presenter Nick Ferrari asked directly whether the proposed measures would include killers of police officers.

Rayner replied: “Yes.”

Earlier, housing minister Sally Jameson had also told broadcasters that she was confident the justice secretary would find a way to prevent Harper’s killers from being released early.

“He’s looking for solutions, and a solution’s been identified,” she said.

The government is therefore attempting to reassure Harper’s family that the issue is being treated as a priority.

However, the wider prison crisis remains a significant obstacle.

Thousands of prisoners are expected to benefit from the sentencing changes introduced as part of efforts to tackle overcrowding.

The government initially estimated that around 6,000 prisoners could be released early.

That figure has since fallen to approximately 5,000 following the introduction of exemptions for some serious sexual offenders.

Burnham has warned that the prison system is under extreme pressure.

Last week, when announcing the additional exemptions, he said he had pushed the system “to the very limits of what is possible” without risking prisons reaching capacity and collapsing.

He has nevertheless now indicated that further options remain available.

His proposal to create additional capacity is intended to reduce pressure without creating a situation in which prisons are unable to accept newly convicted offenders.

In his statement, Burnham also stressed that murderers had always been excluded from the early-release changes.

He pointed to the newly announced exemptions covering rapists, serious child sex offenders and grooming offenders as evidence that the government had already gone further than originally planned.

But he acknowledged that victims of other crimes remained concerned about early release.

“I am doing all I can, but it is simply not possible to prevent all offenders from being released early without the prison system collapsing,” he said.

That warning highlights the tension at the heart of the controversy.

The government wants to keep dangerous offenders behind bars for longer, but it also needs enough prison places to accommodate people entering the system.

The Harper case has become a particularly powerful symbol of that dilemma because of the circumstances surrounding the officer’s death.

PC Harper was 28 when he was killed in August 2019.

He had been married to Lissie for only a month when he was called to investigate the theft of a quad bike in Sulhamstead, Berkshire.

As the suspects fled, Harper became caught in a strap attached to the back of their vehicle.

He was dragged along a country road and suffered fatal injuries.

Henry Long was driving the vehicle, while Cole and Bowers were passengers.

All three were convicted of manslaughter.

Long received a 16-year sentence and is not eligible for the early-release scheme because of the type of sentence imposed on him.

Cole and Bowers, however, received 13-year sentences and fall within the category affected by the sentencing changes.

That distinction has become one of the most controversial aspects of the case.

For Harper’s family and many police officers, the fact that two of the men could leave prison significantly earlier than expected is deeply difficult to accept.

Lissie Harper has previously argued that those responsible for killing emergency workers should face particularly severe consequences.

Her campaign contributed to the introduction of Harper’s Law, which created mandatory life sentences for people convicted of killing emergency workers while committing a crime.

The possibility of Cole and Bowers being released early has therefore raised questions about whether the current sentencing system undermines the principle behind that campaign.

The government now faces pressure to demonstrate that it can reconcile the need to reduce prison overcrowding with its promise to protect victims and keep the most dangerous offenders in custody.

Burnham said the government would seek discussions with other political parties before the Justice Secretary’s proposals are presented to Parliament.

The aim, he said, was to secure the widest possible political and public consensus.

For Harper’s family, however, the immediate issue remains straightforward.

They want the men convicted over his death to remain in prison.

The prime minister has now given them a stronger indication that this may be possible.

But until Norris presents the government’s plan in September, uncertainty remains.

Burnham’s statement offers a promise rather than a final legal mechanism.

The government must still determine how additional prison capacity can be created, how the scheme can be altered without unfairly affecting other prisoners and whether its proposed solution can withstand legal scrutiny.

For now, though, the prime minister insists he has not given up.

And after weeks of anger, uncertainty and conflicting messages, his declaration that he is “increasingly confident” of keeping Harper’s killers behind bars will be closely watched by his family, the police and thousands of members of the public who have demanded the same outcome.