Ontario's Progressive Conservatives say the Liberal government used the code name Project Vapour to hide the cost of cancelling a generating station in Oakville from the public.

The Opposition uncovered the Project Vapour code name in 20,000 documents released last Friday on the cancelled gas plant in

Oakville and another in nearby Mississauga, which followed 36,000 pages of documents released last month.

PC energy critic Vic Fedeli says Friday's second batch of documents is proof Premier Dalton McGuinty and several cabinet ministers misled the legislature by insisting all the relevant documents had been released Sept. 24.

Fedeli says McGuinty resigned suddenly Monday and prorogued the legislature knowing his government would face a second contempt motion.

The first contempt motion against Energy Minister Chris Bentley, which was scheduled to go to the finance committee for public hearings, was killed — along with question period and all other legislative business — by Monday's surprise prorogation.

The Liberals say it will cost taxpayers $230 million for cancelling the two energy projects, but the Tories and New Democrats say it's at least triple that amount and was used to save Liberal seats in last fall's election.

Code names common practice, Liberals say

The Liberals say it's common practice to give code names to sensitive projects involving negotiations, especially with private companies.

The Tories and New Democrats said Wednesday they were convinced the Liberals still had not given up all the documents on the cancelled energy projects.

"With code names and curiously missing emails, this package of documents makes clear that Dalton McGuinty and his government are still not complying with an order of the House, and are still not telling Ontarians the truth," said Fedeli.

"With Project Vapour coming to light, no wonder Dalton McGuinty resigned."