Doug Ford spent much of the Ontario election's northern debate attacking the NDP, which has traditionally enjoyed support in the region and is seeing momentum in the polls, while Liberal Premier Kathleen Wynne stayed on the defensive.

During Friday's debate, the Progressive Conservative leader warned voters about an NDP government, harkening back to the last time they held power, in the 1990s, saying they "destroyed this province."

He also slammed an NDP candidate who he says was a professional anti-mining activist. The NDP used to claim to fight for workers in the province's mines, mills and factories, but now they serve "downtown Toronto elites" and environmental "extremists," Ford said.

Ford asked party leader Andrea Horwath which NDP is running in this election but she turned the tables, noting Ford has not yet released a fully costed platform.

"I'm going to be the NDP that is going to be honest and transparent about my plan," she said. "It was launched two weeks before this election even started. It is fully costed, it has a fiscal plan that goes with it. Mr. Ford, where's your plan? How are people going to know who you are going to be if you don't provide a plan?"

Ford said he would not let "a bunch of extremists (in) downtown Toronto decide what the people of the north are going to do."

Horwath laughed, saying, "what you're going to do is drive a bulldozer through the Ring of Fire and pave over the Greenbelt — talk about extremism."

Ford has previously reversed an election promise to allow housing construction in the Greenbelt, a large protected greenspace around the Greater Toronto Area, and has spoken about driving a bulldozer himself to get roads built in the Ring of Fire.

The Liberal government has long promised to develop the region and last year secured an agreement with three First Nations to start road construction to one of the world's richest deposits of chromite — used to make stainless steel — as well as nickel, copper and platinum, valued at anywhere from $30 billion to $60 billion.

While Ford criticized the Liberal record on the issue as being all talk, Wynne says he has another thing coming if he believes the Ring of Fire will move ahead without respectful dialogue.

"I acknowledge the conversation around the Ring of Fire with companies and with First Nations, it has taken time, but we are doing it in a way that is going to ensure that everyone who has the opportunity to benefit is actually going to benefit," Wynne said.

The previous day of the campaign also saw the governing Liberals set their sights on the NDP, as polls suggest momentum is building for the New Democrats, leaving the Liberals trailing in third place.

Ford comments on Wynne's smile, again

Perhaps the most memorable moment of the morning came after the formal debate ended.

After Liberal Leader Kathleen Wynne and PC Leader Doug Ford had apparently finished their handshake, Wynne tried to break away and walk off the stage in the opposite direction. Ford kept his grip, however, prompting Wynne to turn back and face him.

"I still like that smile," he said, smiling himself.

At the end of the Northern Debate in Parry Sound, PC Leader Doug Ford shook Liberal Leader Kathleen Wynne's hand and compliments her smile for the second time this week. 0:09

Wynne took questions from reporters after the debate and was asked about the interaction.

"I just turned away because I'm not sure what my smile has got to do with making good policy for the north or anywhere else in the province," she said.