A law that would make drugs for personal use a health rather than legal issue is being seen as a watershed moment that will bring about de facto decriminalisation, despite Government claims to the contrary.
The Misuse of Drugs Amendment Bill is the Government's response to the synthetic cannabis crisis and would classify synthetic drugs AMB-Fubinaca and 5F-ADB as Class-A substances; dealers of Class-A drugs face a lifetime in prison.
But in a move described by the Police Association as an under-the-radar change, the bill would also codify police discretion into law.
It would mean a prosecution for drug use or possession - regardless of which drug - should be pursued only if it was in the public interest, taking into account whether a "health-centred or therapeutic approach would be more beneficial".
Those provisions have prompted drug law reform advocates, the Police Association, the Law Society and the National Party to describe it as a watershed bill that effectively means decriminalisation of all drugs for personal use or possession.
"It's the biggest thing in drug policy in 40 years," Drug Foundation executive director Ross Bell told the Herald.
"It enshrines in law what this Government and the previous Government has been quite comfortable with, and that is the general shift away from the punitive War on Drugs approach to a health-focused approach.
"It will have a huge impact for thousands of people who have been unduly punished every year, and open the door to therapeutic help."
Former methamphetamine addict Pania Barry backed the move. While she did not have a criminal conviction, any steps that would keep people out of the justice system and get them help to overcome their addiction were positive, she said.
According to Ministry of Justice statistics, the number of people charged for drug use or possession as their most serious drug charge halved between 2009 and 2013.
In 2018, 4114 people were charged with possession or use as their most serious drug charge, with 3188 convicted.
This was a sharp decline from 2009, when 8268 people had possession or use as their most serious drug charge.
Yesterday the Law Society and the Police Association told the health select committee, which is considering the bill, that it would effectively decriminalise all drug use and possession because it would be easy to argue in court that every user would benefit more from a therapeutic approach than a prosecution.
Association president Chris Cahill told the committee police would move from a default presumption to prosecute to one of non-prosecution for all drug users, which would lead to a "dramatic" decline in police charges.
The association did not have a position for or against decriminalisation but it was an issue that should have wider public debate rather than be "slipped in" to a bill, he said.
After the hearing, Cahill told the Herald that if the Government wanted police to use discretion, it should drop the clause in the bill that said "a prosecution should not be brought unless it is required in the public interest".
Law Society spokesman Chris Macklin told the committee the wording in the bill would make it easy for a lawyer to argue that a prosecution should never be brought. He could not think of any reason a possession charge would be in the public interest.
Prime Minister Jacinda Ardern, Police Minister Stuart Nash and Health Minister David Clark all pushed back on the claim that the bill was de facto decriminalisation for personal drug use or possession.
Ardern said police could prosecute drug users if it was in the public interest.
"There will certainly, I'm sure, be circumstances where that might be the case."
Nash said the bill aimed to take a health approach, not a criminal approach, but it was not decriminalisation.
"If it is the public interest to prosecute, police have the ability to do so, but by and large, we want police to take a health approach because the evidence shows that this is much more effective in getting people out of the web of addiction."
Many submitters to the committee agreed that synthetic drugs were often used to escape trauma, and it was important to help, not criminalise society's most vulnerable.
Bell told media after the hearing that without a substantial increase in drug treatment services, a health-focused approach to reduce drug-related harm was pointless.
"There's huge expectations on the Wellbeing Budget later this month that the Government will prioritise mental health and addictions, but I'm really nervous they won't meet our expectations."
He wanted annual funding for alcohol and drug treatment services to double to $300 million.