Tuesday night's debate is especially important for New Democrat Leader Andrea Horwath, according to pollster Nik Nanos.
Nanos told Madely in the Morning, Horwath has slipped nine percentage points in the individual leader category in the past 30 days and she'll be looking to regain some ground.
"The thing is that realistically that she has to tear down Kathleen Wynne," he said. "You know, if people are in the Tim Hudak camp, the reality is is that those voters are fairly solid in terms of supporting Tim Hudak and the Progressive Conservatives."
"It's the votes between the Liberals and the New Democrats and switchers between those two parties that are critical," he added. "For Andrea Horwath, I would expect that tonight, she's probably going to take the bazooka out and try to put a broadside into Kathleen Wynne and to try to remind people about the last 10 years of liberal government and things that some voters might not be happy about."
The latest polls show the Liberal party with a slight lead over PCs.
"The Liberals do have the upper hand when we look at all voters, but when we look at likely voters, for example, the Abacus survey shows that it's a much tighter race," said Nanos.
You can listen to the debate live on CFRA starting at 6:30 or tune in to CTV Ottawa.