Mr Cull told councillors at yesterday's planning and regulatory committee meeting the Psychoactive Substances Act gave councils the power to develop policies to control the location of legal-high retailers.
However, the Ministry of Health's Psychoactive Substances Regulatory Authority could ignore those policies when issuing licences to those retailers, Mr Cull said.
It was among concerns raised during a gathering of South Island councils in Invercargill last week.
At yesterday's committee meeting, Mr Cull gave a blunt assessment of the legislation: ''Ham-fisted would be a compliment.''
His comments came as councillors approved a submission to the ministry, which was consulting councils on regulations that would provide more detailed direction on implementing the Act.
The submission, written by planning and regulatory committee chairman Cr David Benson-Pope, reiterated council concerns and warned the new approach could create difficulties.
Either the authority would not consider council policies before deciding licences or, if it declined a licence based on council policies, those decisions ''could be challenged in court''.
''This will mean Dunedin's [policy] will be unenforceable and that the wishes of our community could be overridden,'' Cr Benson-Pope warned.
Mr Cull told yesterday's meeting the new approach legalised and legitimised ''toxic'' substances but gave councils ''inadequate'' tools to control the process.
The legislation was inconsistent with the approach taken to control alcohol and gambling in communities, but politicians in Wellington appeared uninterested in the potential problems - and costs - created for councils, he said.
''They cost our ratepayers money and their apparent disinterest in Parliament ... seems, to me, remiss,'' Mr Cull said.
''It's unfortunate that ... parliamentarians don't seem to understand the implications of their own legislation.''
His comments came after he and Dunedin-based National MP Michael Woodhouse engaged in a public war of words over the issue last week.
Mr Woodhouse told The Star newspaper Mr Cull had been ''publicly hand-wringing'' over the issue, when the council needed to ''get off their butts and get moving'' to complete work on its policy for Dunedin.
Mr Cull responded by saying the Government had ''made a balls-up'' of the legislation, while the council was working ''prudently'' to avoid wasting money ''trying to plug holes in inadequate central government legislation''.
Council liquor licensing and projects officer Kevin Mechen told yesterday's meeting he had completed a draft local approved products policy (LAPP) that would control the location of psychoactive substances retailers in Dunedin.
It and the council's draft local alcohol policy would be considered together by councillors at a non-public workshop on April 28, before being released for public consultation following the meeting.
