TORONTO—Ontario auditor general Jim McCarter will unveil his report into the cancellation of the Mississauga gas plant on April 15.
The governing Liberals pulled the plug on the plant, which was already under construction, in the dying days of the 2011 election campaign.
Opposition parties have accused them of cancelling the plant to save Liberal seats.
The Liberals say the cost of relocating the Mississauga plant to Sarnia will cost $190 million.
They have claimed that the cancellation of another plant in Oakville in 2010 will cost taxpayers $40 million, but have since admitted that it could be more.
An energy consultant testified at a legislative committee that the cost is about $638 million.
Premier Kathleen Wynne has asked the auditor general to look into the Oakville cancellation.