A report into the massively overspent Spinnaker Tower project - expected to be highly critical of Portsmouth Council - is out on Friday.
The still-unfinished tower is to cost taxpayers £8.4m
It has already claimed one casualty - Leo Madden, leader of the council's Labour group, resigned last week.
As leader of the council in 1999, Mr Madden commissioned the Millennium project, promising it would not cost taxpayers - who now face an £8.4m bill.
The project has been hit by delays, and was originally to be finished by 2000.
Built on Gunwharf Quays, near Portsmouth Harbour station, the Spinnaker Tower is to offer spectacular views across the harbour for an expected 500,000 visitors a year.
The development was first approved by the Millennium Commission in 1995.
The Semmens report is an 18-month internal investigation by the council.