It follows former NSW Director of Public Prosecutions Nicholas Cowdery supporting mercy for Bronson Blessington.

In Wagga to present an Order of Australia Medal to a resident, NSW Governor David Hurley declined to comment and on Saturday, a spokesman reiterated the Governor would act on the advice of his ministers.

Lawyer Peter Breen has applied for clemency for Blessington under the NSW Governor’s royal prerogative of mercy, citing his rehabilitation and “exemplary” discipline in prison.

The application is being assessed by NSW Attorney-General Gabrielle Upton.

"This is a case for the exercise of the prerogative of mercy," Mr Cowdery said, adding he was speaking in a personal capacity and not for the NSW Sentencing Council.

"Just putting someone in a box and holding them until they die is objectionable, particularly when you do this to someone in their teens," he said.

"I don't think there is any rational justification for it at all. It's revenge pure and simple."

While retribution was one principle of the criminal justice system, Mr Cowdery said rehabilitation was another.

"Families of the victims have a legitimate say but they don't have – and they shouldn't have – the power to dictate what is going to happen," he said.

"Their views must be taken into account but they must be weighed against the other considerations."

Mr Cowdery is not the only person to voice his support for seeing Blessington released.

The United Nations found the prison term and remote chance of parole constituted “cruel, inhuman or degrading punishment” in 2014.

It also said the sentence breached the UN Convention of Rights of the Child as Blessington was just a teenager when he was found guilty of Ms Balding’s murder.

Ms Balding’s family has fiercely opposed the release of Blessington.

“I’ll show him the same mercy he showed my sister,” Ms Balding’s brother David told The Daily Advertiser last week.

“He should not be out of jail until he is dead.” Blessington was 14 years old when he took part in the abduction, rape and murder of Janine Balding in September 1988, one of the state's most notorious crimes.

Currently, Blessington can only be released if he’s about to die, or incapacitated.