''I am not interested,'' Mr Cull said yesterday when told of the debate proposed by Star Trust spokesman Grant Hall, who represents about 80% of the legal high industry.
''The issues have been commented on by health professionals and by law enforcement and they are much more competent to comment on the facts than I am,'' Mr Cull said.
Mr Hall had earlier told the Otago Daily Times he wanted to publicly debate the issue with the mayor over his stance which ''looks like political opportunism''.
''If he generally cares about the welfare of local citizens in Dunedin, and he is worried about legal drugs and the impact on the community, than why isn't he threatening to boycott local liquor stores [as alcohol] kills dozens of locals every year?''
Mr Cull rejected any accusation he was electioneering.
''He can sound off about what he likes. I would rather stick to the facts. And the facts are that this is causing a lot of trouble and issues in our community.
''For his information that would happen whatever the year was, it is an absolutely silly thing for him to be saying. He is making a connection between the effects of a drug and election year; I would suggest he has been imbibing a bit much.''
Last week, Mr Hall said the product was statistically safer than alcohol. However, Mr Cull said all drugs, including alcohol, caused problems in the community.
''I am saying, in this instance, there is no measure in place at the moment to deal with the indiscriminate sale and use of these particular synthetic cannabinoids.
''In the absence of any legislative means to deal with it, I am just suggesting it is the community that is suffering, and it is the community that needs to grab hold of the issue and deal with it itself.''
Synthetic cannabis was a topic of discussion yesterday for Labour South MP Clare Curran, and visiting Labour MP Kris Faafoi at the Otago Corrections Facility and with Dunedin police.
Ms Curran said concerns were raised regarding the product, and she planned to visit dairies in her electorate to discuss the issue.
