Andy Burnham is under intense pressure over the early release scheme (Image: Getty)

Labour’s disastrous early release scheme faced fresh fury from domestic abuse campaigners amid mounting suspicions of exemptions for some killers. Ministers are considering barring all prisoners convicted of “unlawful manslaughter” from early release in a bid to keep PC Andrew Harper’s killers behind bars.

But others, such as those convicted of “voluntary manslaughter”, would still be eligible for early release, according to the chair of domestic abuse charity Refuge. Some domestic killers are convicted of this after claiming to have lost control in the moment, suffered a sudden rush of rage or on the grounds of diminished responsibility.

Hetti Barkworth-Nanton, chair of the Refuge domestic abuse charity, wrote: “You cannot be considering exempting just unlawful act manslaughter from early release.

“Voluntary manslaughter, a far more serious conviction being murder with a mitigating factor, must be exempt before the less serious UAM [unlawful act of manslaughter].”

Shadow Justice Secretary Nick Timothy said: “Labour’s early release scheme has been utterly shambolic.

“They are making up policy as they go along.

“At every stage, Labour have said they could not do any more and then U-turned. No one believes them anymore. They must bring forward legislation to stop the release of dangerous criminals including the killers of PC Harper.”

Prime Minister Andy Burnham dodged questions over the rumoured exemptions, insisting only that he is doing “everything possible” to keep PC Andrew Harper’s killers, Albert Bowers and Jessie Cole behind bars.

A former leading judge has warned it would be “unlawful” to block solely Bowers and Cole from early release while freeing other prisoners convicted of the same offence.

However, Lord Thomas of Cwmgiedd said the rule change surrounding the type of manslaughter could be workable in practice.

Some 5,000 people are expected to be released early under sentencing changes, down from 6,000 after ministers excluded rapists, “serious” child sex offenders and predators convicted of grooming offences from the scheme designed to tackle overcrowding in jails.

Many convicts will be out after spending just a third of their jail term in prison.

Andy Burnham will present changes to Parliament (Image: Getty)

And those sentenced to four years or more will only be let out after serving 50% of their sentence behind bars.

The first tranche of releases has been delayed – from September to October. Criminals handed sentences of less than 18 months will be the first to benefit from Labour’s softest sentencing reforms in a generation.

The Prime Minister told reporters: “I’ve said I want to do everything possible to ensure we don’t see the release of people involved in the killing of Pc Harper and other individuals.

“I recognise that it’s very hard for his family. The anniversary of his death passed just at the weekend, so we understand that this is a difficult time.

“But it is important, given the public concern, that I do everything possible to get this right. That I do everything possible to minimise early release. That’s why we’re looking at every way I can do that, with the Justice Secretary, and we’ll present our findings in two weeks’ time.”

Asked about the specific exemption, Mr Burnham said: “At this moment in time, this is speculation, because I asked the Justice Secretary to develop a plan to maximise public safety and minimise the early release of prisoners.”

Lord Thomas, an independent crossbench peer who previously served as lord chief justice of England and Wales, told BBC Radio 4’s Today programme: “People are found guilty of manslaughter in three different circumstances.

“One, because they’ve been charged with murder and have a specific defence.

“Secondly, because they have committed an act which is grossly negligent that has resulted in death.

“And thirdly, involuntary manslaughter…, where there’s been an unlawful act such as a punch, someone’s fallen over, hit his head on the kerb, and died.

“That is the unlawful act manslaughter which they’re seeking to exempt.

“So it is quite possible to distinguish the three types of manslaughter.”

Lord Thomas said “it may not be that straightforward” for prison staff to determine which type of manslaughter an inmate committed from their prison records.

But, he said, it “should be relatively easy to tell that from the sentencing remarks, which are always transmitted with the prisoner’s record”.

The Ministry of Justice said: “Public safety will always be our priority. We are fast-tracking a plan to keep more of the most serious offenders behind bars, on top of murderers, anyone on life sentences and those in prison for rape, serious child sexual abuse and grooming offences who are already blocked from any changes.”