A life sentence will literally mean life for murderers who already have violent records, says the National Party's policy on parole announced today.
National will abolish parole for the worst repeat violent offenders.
And it says this will require a new $314 million prison to hold them and an extra $43 million a year to keep them there.
Under the policy, repeat violent offenders will have to serve every day of a sentence if they have previously been convicted of a violent crime and sentenced to five years or more in prison.
This will mean a murderer with a violent record will stay in prison until they die.
If a criminal sentenced to seven years for an aggravated robbery already has a serious violence conviction, they will serve the full seven years.
National leader John Key said today: "They will serve their full life sentence inside prison."
The "life means life" sentence would have applied to high-profile offenders such as prison-van basher George Charlie Baker, RSA triple-killer William Duane Bell and samurai sword assailant and killer Antonie Dixon.
All have been sentenced to lengthy non-parole periods and may not be released anyway, but National's policy would deny people like them any chance of being free again.
It is understood National's research shows that of the 144 offenders convicted of murder since 2002, 10 would be in this category.
Preventive detention - a jail sentence with no release date set - can be imposed on serious or repeat offenders.
But parole is still available and National says that since 2002, five offenders sentenced to preventive detention have been released.
The policy would have a big effect on the full spectrum of violent crime. Repeat robbers, repeat rapists and those who repeatedly commit violence within the home would not get parole.
Those denied parole under this category would also be monitored for a fixed term when they were released, "rather than being left to their own devices".
It is understood National believes an additional 572 offenders could be in prison by late 2011 because of the policy.
This would require a new jail, which the party has costed at $314 million, and an extra $43 million a year in prison operating costs.
Prime Minister Helen Clark this morning described the National policy as vindictive. She said that under current law some prisoners were not released.
"It's very easy to say lock the door and throw the key away," she said on TV One's Breakfast programme.
"A lot of these long-term prisoners, over time start to change their behaviour, some become very religious.
"The National Party's attitude is they don't care about that at all, they just want to be vindictive."
Offenders are now eligible for parole after serving one-third of their sentence, unless a longer non-parole period has been imposed. Labour has amended parole eligibility to two-thirds of the sentence, although this is yet to come into force.
National's policy says "parole is not a right for prisoners, it is a privilege".
Offences that will lose an offender the right to parole if they offend again would also include attempted murder, kidnapping, rape, grievous bodily harm and some serious assaults.
National leader Key promised this year that one of the first things he would do if he became prime minister would be to toughen parole, bail and sentencing laws.
The pledge followed an Asian anti-crime march in July, prompted by a spate of violent crime in South Auckland.
But the parole policy is not as hard-line as National's 2005 policy under Don Brash, which proposed abolishing parole for all serious offenders. It would also have required new jails to house up to 3000 extra inmates.
The policy was criticised by groups such as the Howard League for Penal Reform, which said it was a 19th-century idea and showed a lack of understanding of the purpose of parole.
- with Claire Trevett, NZPA