Arguments for cannabis law reform, and calls for politicians to stop "running scared", are expected at a drug summit in Wellington to be chaired by broadcaster Ali Mau.
Helen Clark could return to Parliament to discuss decriminalisation at the summit in July, and others are expected to voice frustration at drug law inertia, and what they see as an overemphasis on punishment.
The suffering people endured while waiting to get medicinal cannabis approved was one reason Mau said she was interested in drug law reform.
"You'd have to be made of ice to not be moved by Helen Kelly's story," she said.
Trade union leader Kelly died of cancer in Wellington last October, aged 52.
Her campaign in support of legalised medicinal cannabis use for people enduring painful illness energised the debate around access to medicinal cannabis products.
Laws were relaxed in February, but access to the drugs remained tightly controlled.
Drug Foundation executive director Ross Bell has long expressed frustration at the slow pace of drug law reform. In particular, he said the 1975 Misuse of Drugs Act was antiquated and unfit for purpose.
It had not tackled high rates of drug use and abuse, but instead had "burdened tens of thousands of young people and Maori with criminal convictions".
Mau said this week: "I share Ross' chagrin, or pain if you like, that the pace of change in New Zealand is way too slow."
She had noticed a shift in public attitudes in recent years, with people increasingly voicing support for decriminalisation..
"Three years in talkback radio has made me realise how strongly New Zealanders feel about this issue ... my listeners are not as conservative on this issue as the Government might think New Zealanders are."
Mau will not speak at the Parliamentary Drug Policy Symposium, but a dozen women with backgrounds in drug and alcohol research, politics, law and public health have confirmed their attendance.
"I've never seen a lineup as impressive," Mau said.
Clark, who marked her last day as administrator of the United Nations Development Programme on Wednesday, was in discussions to speak at the summit.
"I've invited her because, at the UNDP, she did a ton of work around decriminalising drug use and sex work," Bell said.
Maori Party founder Tariana Turia was expected to discuss issues affecting Maori and wider criminal justice sector reforms on July 6.
"We've got leading Maori academics who are probably going to disagree with each other," Bell said. "Some are for drug law reform and others are more conservative."
Bell hoped politicians would agree that drug law reforms were needed, and might realise they could make drug reform campaign promises instead of "running scared".
He was excited to have two speakers with knowledge about North American drug law issues lined up to speak at the conference in Parliament.
Former Canadian deputy prime minister Anne McLellan, who headed that country's task force on cannabis legalisation and regulation, will speak on July 5.
Alison Holcomb, who drove efforts to legalise cannabis for recreational use in the state of Washington, will also address the two-day conference.