Prime Minister John Key admits the Government's proposed crackdown on bail will affect only about 50 offenders a year.
The changes outlined by Justice Minister Simon Power this morning will cost about $4.5 million and will be funded out of existing budgets.
Key said there was already a reverse onus of proof for offenders seeking bail but the changes extended that for a specific high risk group the Government didn't believe should be in the community.
People charged with murder or serious drug offences will have to prove they are not a public risk before being granted bail under the changes announced today.
Power said the changes would improve public safety and were the second half of a 2008 election promise by National.
Placing the onus on defendants to prove they are not a risk to the public takes the burden off prosecutors having to show they are likely to reoffend while on bail.
The change will apply to those charged with murder, because of the seriousness of the crime, those charged with serious class A drug offences, because a third of such defendants reoffend while on bail, and to those charged with violent and sexual offences where there is a history of sexual or violent offending.
The Bail Amendment Bill, which will be introduced to Parliament early next year, will also make it clear that bail would not be granted for return of information, will increase the penalty for failure to answer police bail, put electronic monitoring into legislation and reduce the number of situations where a defendant has a right to bail.
Power said the Government would also strengthen bail for young defendants by requiring those aged 17-19-years-old who had served jail time to be subject to adult bail tests and allowing the court to detain defendants under 17 who had significantly breached bail conditions.
Police would also be enabled to take home young defendants found to be in breach of court-imposed curfews.
Power said they were designed to balance a defendant's rights with public safety.
"These changes will improve public confidence in the bail system and ensure that bail will be harder to get in marginal cases where the court would previously have had no choice but to release a defendant on bail."
Key said National was keeping its campaign promise to make New Zealand a safer place.
The Government had passed 18 laws aimed at reducing crime since it came to office.
"No other government has passed more legislation when it comes to law and order than this Government," he told a senior citizens meeting on the Kapiti Coast this morning.
Key said people were innocent until proven guilty, but that right must be balanced with the need to ensure public safety.
When National came to power it reversed changes to bail laws made by Labour which it claimed made it easier for people to get bail.
It had said Labour's amendment meant previous bail breaches, or offending while on bail, may not have been considered relevant when deciding whether to grant bail.
The changes, which went through two months of public submissions, will cost $4.5 million a year.
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