Former Prime Minister Helen Clark says a bill that would quadruple the maximum prison sentence for people supplying synthetic cannabis reflects a failed war on drugs mentality.

Photo: RNZ / Claire Eastham-Farrelly

National MP Simeon Brown's bill would extend the maximum prison term for supplying synthetic cannabis from two years to eight.

It passed its first reading at Parliament last night - supported by National and New Zealand First MPs.

At a conference on drugs at Parliament today, Ms Clark, who is a member of the Global Commission on Drug Policy, said the global war on drugs had failed, with devastating consequences for individuals.

Ms Clark said the proposed synthetic cannabis law change was more of the same.

"That is heading in the war on drugs direction which isn't going to work - but going to a select committee to a bill is one thing, what will come out the other end.

"And I think all the people who know about drug policy, who know what's happening around the world, need to come to the (select) committee and spell it out how it is."

Ms Clark said the countries with the harshest drug policies had the highest rates of drug related harm.

"We look at the United States and Russia which both have very harsh policies at the federal level - they also have very high rates of drug induced death."

Ms Clark said it was time for New Zealand to have a fresh look at its drug policy.

"We have to look at the evidence of what works - and if we looked at Portugal or to Switzerland or any number of countries now we see more enlightened drug policies, which are bringing down the rate of death and not driving up prison populations."

'People are making money out of people's misery'

However, Mr Brown said the people supplying synthetic cannabis were merchants of death and needed to be punished.

"My bill's not locking up drug users, it is not locking up those who are victims of drug abuse. My bill is targeting those who are selling it."

He did not see any need to change the law on drugs.

"We don't decriminalise something for the sake of it, we don't just make it legal, we have laws in place because these things are causing harm.

"People are making money out of people's misery and those people should be locked up."

Drug Foundation executive director Ross Bell was disturbed that National and New Zealand First MPs had backed the bill.

"Getting tough, having longer sentences doesn't get rid of the problem, it makes the problem worse - so it's really disappointing to see Parliament last night go for this more punitive response."

The synthetic cannabis bill will now be considered by the Justice Select Committee.