A fierce Forsyth Barr Stadium opponent believes the Dunedin City Council should threaten to mothball the facility.

It follows a report recommending the city council take on $30 million of debt currently sitting with Dunedin Venues, with ratepayers stumping up an extra $18 million.

Stadium opponent Bev Butler says the costs have blown out, while local heavy hitters in the private sector who originally promised to inject capital, have failed to deliver.

She says the council should put the ball back in their court.

"And I think the time has come for the council to stand up and say we're not bailing you out anymore. You're the ones responsible, you need to come to the party."