TORONTO -- Ontario Premier Kathleen Wynne is disputing opposition charges that she was at least partly to blame for driving up the cost of cancelling gas plants in Oakville and Mississauga to $1.1 billion.

The NDP say Wynne's signature on a cabinet document promising to make TransCanada Enterprises "whole" severely weakened the province's negotiating position with the developer of the cancelled Oakville plant.

Wynne says she was advised that a lawsuit could have been an even more expensive option than negotiating a new deal with TransCanada, so the government wanted to avoid going to court.

Wynne told the justice committee she wasn't directly involved in the Liberals' decisions to scrap the gas plants prior to the 2011 elections, even though she was the party's campaign co-chair.

The Tories also went on the attack against Wynne for signing the document that they say gave the developer a stronger hand to wring compensation from the government.

Wynne also denied originally low-balling the cost estimates of the gas plant cancellations, saying there were lots of figures being bandied about so she asked the auditor general to determine the real figures.

In her second appearance at the committee hearings, Wynne again apologized for the expensive decisions to cancel the gas plants, and said she had made changes to make sure it won't happen again.