Christopher Luxon speaks to media at the National Party conference. Photo: RNZ / Giles Dexter
National plans to toughen up sentences if elected by imposing a 40 percent limit by which a judge can reduce a sentence.
When handing down a sentence, judges take a monetary or temporal starting point based on the nature of the crime. They then consider aggravating or mitigating factors, and add on or reduce to the sentence accordingly.
Judges can reduce sentences according to a range of factors, such as the accused pleading guilty or their personal circumstances.
National said there was a lack of clear guidance for the judiciary, which led to "substantially reduced sentences that fail to adequately denounce the severity of the crime, recognise the harm caused to the victim, and deter others from committing similar offences".
If elected, it would rewrite the Sentencing Act to impose a maximum sentence discount of 40 percent, regardless of how many mitigating factors there were.
At the party's annual conference on Sunday, National leader Christopher Luxon said the discounts undermined the purpose and impact of sentences, as well as the public's faith in the courts.
"Victims and the public risk losing faith in the justice system when criminals receive such hefty discounts to their sentences that they don't reflect the harm caused.
"Putting a maximum limit on sentence reductions strikes the right balance between denouncing criminal behaviour and allowing judges discretion."
National also said it would get rid of taxpayer funding for cultural reports, which allow someone to speak to the court about an offender's background. It said more than $19m had been spent on nearly 8000 reports since Labour took office in 2017.
"This has led to a thriving cottage industry. National will retain the right of an offender to ask the court to hear from a person known to them, but will end taxpayer-funded written reports," Luxon said.
The money freed up from cancelling the cultural reports - which it estimates as $20m over four years - would instead fund more victim support measures such as counselling, or transport to attend court.
National also proposed expanding eligibility to the 29 rehabilitation programmes on offer in New Zealand to all prisoners on remand, rather than the three currently available.
'An egregious overreach' - Labour responds
Labour Party justice spokesperson Kiri Allan said the Sentencing Act was fit for purpose, and politicians should not impinge upon the judiciary.
Labour justice spokesperson Kiri Allan Photo: RNZ / Samuel Rillstone
"I think it's an egregious overreach, myself," Allan said.
"The trust that we must have in those frontline judicial officers - that they know their job best, they know what they've been charged to do. And where I think Mr Luxon took it a step too far today is essentially saying that we politicians know better than the judiciary."
Allan also criticised National for not fronting with numbers on how much it would cost to keep people in the corrections system for longer, or how many people it would affect.
"How many more prisoners does he want to incarcerate? He wants longer sentences, well that's going to cost money."
National corrections spokesperson Mark Mitchell said his party would be able to answer those questions if it got into government come October.
"That is when we'll start rolling out our policies, and then we'll start to get a feel in terms of how those policies are starting to work," Mitchell said.
"And that will determine the pipeline of people coming into the corrections system, how many programs we have to deliver, how many people we have in remand, how we start to have an impact on public safety."