But Ms Butler would not say yesterday whether any action would follow the event.
The speakers for the event at the Dunedin Town Hall, at 7pm on March 29, for which broadcaster Dougal Stevenson is master of ceremonies, are Dunedin businessman Alistair Broad; Dunedin city councillor Dave Cull; Otago regional councillor Gerry Eckhoff; Dr Robert Ham-lin, of the University of Otago School of Business; Environment Southland chief executive Ciaran Keogh; NHNZ chief executive Michael Stedman; and former Dunedin mayor Sukhi Turner.
Asked how the meeting would help stop the stadium, Ms Butler said "you will just have to come along and see".
She said in a press release a "cool, objective appraisal from a wider range of perspectives" was needed.
"We have heard too much from the same entrenched positions on both sides of the argument."
She said Stop the Stadium representatives would not be speaking, as its position was already well known, but the stadium debate had become more significant because of the economic downturn.
The project was described by a councillor recently as "95% certain", and since dropping Environment Court appeals against it, a judicial review has been the only possible obstacle suggested by Stop the Stadium that could stand in its way.
The organisation has not released any further information on whether it will try to implement a review.
Most of the speakers have been openly anti-stadium, though Mr Stedman and Mrs Turner have not made public statements so far. Mrs Turner could not be contacted yesterday.
Mr Stedman said, while he was not anti-stadium, he had many questions about the issue he felt had not been answered.
The project was an "enormous commitment" for the city, and would affect it for many years.
He did not agree the future of the city depended on the stadium being built; had noted the Rugby World Cup games could be held at Carisbrook if the project did not go ahead; and he was concerned too much information had been withheld because of commercial sensitivity.
"I find that worrying when the citizens are doing the bulk of the paying. There should have been a lot more open public debate."
Asked why he was speaking out after so long, Mr Stedman said it was because he had been invited to talk at the meeting.
