Ontario Premier Kathleen Wynne says she wasn’t involved in the Liberal government’s decisions to cancel gas plants in Oakville and Mississauga.

Wynne told an all-party legislative committee Tuesday that even though she was Liberal campaign co-chair in 2011, she learned about the decision to cancel the Mississauga plant just days before the election through the media.

Testifying under oath Wynne admitted she signed a cabinet document to allow negotiations to proceed on the Oakville plant, but said that was eight months after the project was cancelled in 2010.

Earlier in the day, Colin Andersen, CEO of the Ontario Power Authority, dropped a bombshell, telling the committee that cancellation of the Oakville gas plant will cost as much as $310 million. That’s more than seven times the original cost estimate of $40 million.

In her testimony, Wynne said cost estimates from the energy ministry were constantly changing and complex to calculate.

The committee is probing the government’s decisions to cancel two gas plants — the one in Oakville and another in Mississauga.

The opposition parties estimated before the hearing that the true cost of scrapping the Oakville plant will be hundreds of millions of dollars more than the Liberals have claimed. An auditor’s report on the project will be ready in late summer.