Environment Southland is condemning its chairwoman's so-called unacceptable lapse of judgement in calling a televised talkback programme under an assumed name.
Ali Timms is said to have harangued Invercargill Mayor Tim Shadbolt for almost 10 minutes on the Cue TV show last week.
She claimed to be "Ruby" - a mother of two who was struggling to make ends meet after her husband had been laid off from the Tiwai Point aluminium smelter.
Environment Southland has issued a statement saying there is unanimous disapproval.
It will hold an extraordinary meeting next month to consider the chairmanship.