Ontario Premier Kathleen Wynne said Monday she had no choice but to threaten Progressive Conservative Leader Tim Hudak with a lawsuit after he refused to retract claims she may have overseen the wiping of hard drives in the premier's office.

Hudak, PC energy critic Lisa MacLeod, the Ontario PC Fund and the Ontario PC Party were served with a notice of libel late Friday after getting a cease and desist letter from the premier's lawyer earlier in the week, said Wynne.

"I don't do it lightly, but I want to be able to debate matters of fact," she said after a 43-minute speech at an Italian cultural centre in Toronto.

"The allegations that were made by the leader of the Opposition were very disturbing and so we have taken that action, but it will unfold as part of the legal process." 

Wynne started the legal battle March 30 with an open letter demanding Hudak stop repeating that she "possibly ordered" the destruction of government documents in the gas plants scandal. The premier's letter called Hudak's statements "false, misleading and defamatory allegations that are utterly unsupported" by evidence.

Friday's libel notice included the second "cease and desist" letter from Wynne's lawyer to Hudak, but the PC leader said again Monday that he won't back down.

"No, of course not," said Hudak. "I've got a job to do and we're going to do it and not be intimidated by a series of angry letters coming from Kathleen Wynne and the Liberals." 

Hudak said it's his duty to ask questions about the Liberals' attempts to hide emails, correspondence and other documents on their decisions to cancel two gas plants prior to the 2011 election, at a cost of $1.1 billion. 

"I just wish they'd spend as much time trying to get our economy going again as they are scrambling behind the scenes with lawyers," he said. "I think they've got the wrong priorities."

Both Wynne and Hudak refused to release copies of the libel notice Monday. 

Wynne's office also would not say what damages, if any, she is seeking, but the premier herself said she just wants Hudak to retract his accusations about her having a role in the alleged wiping of 24 hard drives in the premier's office.

During her campaign-style speech Monday, Wynne said that despite the legal wrangling with Hudak, she would stay focused on the upcoming budget, which she knows will trigger an election if the Liberals can't get the NDP to support it.

The premier lashed out at both opposition parties during her speech, but she didn't mention NDP Leader Andrea Horwath by name.

"What Tim Hudak has said he would do is make deep cuts in health care and education and that means teachers, support workers in the school system and nurses would be fired," said Wynne. "I don't know what the NDP would do because they haven't talked about what they would do."

Horwath said again Monday that the NDP want to see the budget before deciding if they can prop up the minority Liberal government for a third year in a row or will agree to join with the Tories to defeat the budget and force an election. The legal wrangling between Wynne and Hudak is nothing but a "side show" to the real scandal surrounding the cancelled gas plants and the attempted cover-up, added Horwath.

"The premier of this province and the leader of the official opposition can send threats back and forth until they're both blue in the face, but what New Democrats want to do is get answers for Ontarians," she said.