The southern mayors are taking the fight on legal highs to parliament and asking for an outright ban.
But the national drug agency says the mayors stance shows they have no understanding of the law.
Invercargill Mayor Tim Shadbolt, Southland District Mayor Gary Tong and Gore District Mayor Tracy Hicks have written an open letter to Health Minister Tony Ryall and Associate Health Minister Peter Dunne asking them to reconsider the consequences of the Psychoactive Substances Act 2013.
The mayors asked for a total ban on psychoactive substances after overwhelming feedback in Southland.
The letter also questions morals around the Psychoactive Substances Act and the responsibility of regulations being forced on councils.
To read the letter click here
The southern leaders have requested a written response before deciding the next step to take.
In a joint statement they expressed their disappointment.
''These synthetic chemicals will lead to significant societal problems and threaten to destroy many young New Zealanders' futures,'' the letter says.
The mayors say they will not stand back and accept the damage the drugs are doing in Southland.
But New Zealand Drug Foundation director Ross Bell hit back saying the letter showed a lack of understanding from the mayors.
The mayors had a responsibility to their communities rather then joining the hysteria, he said.
He labelled the trio's actions as ''petty politics'' rather then embracing the new provisions for mayors under the law.
They needed to stop playing ''silly buggers'' and ''pull their heads out of the sand'' and do something pragmatic, he said.
They were are asking for something that had been tried 10 years ago and did not work, he said.
Gore District mayor Tracy Hicks said the mayors were doing what the whole Southland community had asked for.
''I know this needs to be regulated and managed and maybe it is impossible to ban but if you don't ask, you don't know.''
Invercargill anti-legal-high campaigners, who handed over a petition with 5806 signatures to Invercargill Mayor Tim Shadbolt this week, have welcomed the letter.
Anti- legal- high protesters Diana MacAskill and Debbie Plank said the letter was excellent.
''It is good the mayors have taken notice and are being proactive,'' Plank said.
''I hope it happens now. It has been a lot of hard work to get this far,'' MacAskill said.
- The Southland Times
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