The Tories offered Thursday to cover the costs for the premier to appear via teleconference for the Sept. 23 debate, but McGuinty — the lone holdout in the challenge — didn't bite.
The Liberal leader defended his decision during a tour of the north, saying his staff told organizers in August that the date they'd selected was "not suitable." He never received any alternate dates.
McGuinty said he'd rather discuss northern issues during the televised leaders' debate in Toronto on Sept. 27.
"I want to make sure that the opposition leaders in particular aren't delivering one message up here in northern Ontario and another message in southern Ontario," he said after touring the Essar steel plant in Sault Ste. Marie.
NDP Leader Andrea Horwath tells southern audiences that she wants a moratorium on development north of the 51st parallel, which would kill development of the Ring of Fire chromite deposit and thousands of potential jobs, he said.
"And then she's got another message when she's up here in the north," McGuinty said.
"I think we need to have one debate where we're all on the hot seat, so to speak, where all Ontarians are watching us and our position on northern Ontario issues is one that we deliver in the south at the same time," he said after visiting the Essar steel plant in Sault Ste. Marie.
The NDP said McGuinty's claim that Horwath wants to block development in the north is not true.
"If Dalton McGuinty wants to have an honest debate, he can name the time and the place and Andrea Horwath will be happy to oblige," the NDP said in a release.
Horwath has been pushing for a debate in the north for weeks, saying issues such as unemployment and the high cost of living in that area deserve their own turn in the spotlight.
Tory Leader Tim Hudak accepted the invitation from the Northwestern Ontario Municipal Association on Wednesday.
The opposition leaders have been ratcheting up the pressure on McGuinty to join them because northern Ontario is suffering under his expensive energy policies and high taxes.
"I'll hope he'll take the chance to look northern families in the eyes and tell them why he is ducking the debate in northern Ontario," Hudak said during a campaign stop north of Toronto.
"I wish he'd actually show up Thunder Bay with Ms. Horwath and myself and talk about his plan."
The Liberals say they've requested that one segment of the Sept. 27 debate be devoted to northern issues. However, the broadcasting consortium that's organizing the event plans to let the public decide what the issues should be.
McGuinty made his first northern campaign stop Wednesday with a political rally in Thunder Bay. He toured the Bombardier plant on Thursday morning, where he touted his plan to expand GO Transit service in the Toronto area.
The Liberals are promising to expand GO train service to a two-way, full-day service on all corridors, which they say will double the current number of coaches and support jobs at the plant where the coaches are made.
He was joined by Canadian Auto Workers president Ken Lewenza, who gave the Liberals an unexpected boost ahead of the Oct. 6 election.
The union leader — who traditionally supports the NDP — said he's encouraging some members to support the Liberals in ridings where the NDP are unlikely to win.
"We've decided obviously to support all of the incumbent New Democrats because we think they are an incredibly important voice, and then in the areas quite frankly where it's between the Liberals and Tories ... then I would suggest to them that the alternative is the Liberals," he said.
"That's the reality. At the end of the day, Mr. Hudak has drawn a line in the sand against workers, against good jobs, against good public services, and we've got to challenge that theory."
Horwath shrugged off the union leader's plug for the Liberals.
"Ken Lewenza can stand next to whoever he like," she said in Toronto.
"I know that our plan is one that puts families first, that puts people first, that actually starts addressing the problems that are facing everyday families, putting some real practical solutions in place that start getting people jobs they need, that start making life more affordable."
McGuinty's next stop was Sudbury, where he was to attend an evening rally with supporters.