TORONTO -- Liberal corruption and the Conservatives' plan to cut public sector jobs dominated the Ontario leader's election debate Tuesday, with the $1.1 billion gas plants scandal landing as the very first question for Premier Kathleen Wynne.

The Liberal leader was on the defensive from the very start of the 90-minute debate, forced to apologize repeatedly for the decision to cancel two gas plants prior to the last election and defend soaring electricity rates.

"The decisions around the relocation of the gas plants were wrong," Wynne admitted. "There was public money that was wasted, and in the process the public good was sacrificed to partisan interests."

Wynne said she's taken action to ensure that "the breach of trust between the government and the people" does not happen again.

Progressive Conservative Leader Tim Hudak defended his plan to cut 100,000 public sector jobs while promising to create one million new jobs over eight years, with both Wynne and NDP Leader Andrea Horwath saying he made a basic math mistake.

"I'm so confident in my plan that if I don't carry through and keep my promises in the Million Jobs Plan, I'll resign, I'll step down from office," said Hudak.

"If I don't balance the budget in two years, I'll step aside," the Tory leader told reporters after the debate. "I hope the other two leaders will make the same commitment."

Hudak insisted he would eliminate the $12.5-billion deficit in two years even if Ontario falls into another recession.

Horwath went on the attack early in the debate, lashing out at Wynne for the gas plants cancellations and scandals at eHealth Ontario and the Ornge air ambulance service, while also warning that Hudak's plan to cut existing jobs to create new jobs doesn't make sense.

"You don't have to choose between bad ethics and bad math," said Horwath.

The NDP leader scored her best shot when she asked Wynne point blank why she didn't refuse to sign a document cancelling one of the two gas plants.

"You had a choice when you were going to sign off on those gas plant documents," said Horwath. "Why did you not choose to stand up for the people of Ontario and ensure that those documents weren't signed? Why did you make the wrong choice?"

Wynne responded by saying she's apologized for the gas plants.

"I have taken responsibility for being part of a government that made decisions that were wrong," she said.

The three leaders answered six questions posed by voters on topics including government ethics, job creation, education, transit and the deficit.

Ontario voters go to the polls on June 12.