What's at stake in final Ontario leaders' debate?

Apparently her approach has worked.

Since that debate, the PCs' huge lead has collapsed, the NDP has experienced an unprecedented surge in popularity, and the Liberals who had once contemplated a future as the Official Opposition after 15 years in office now face a potentially humiliating loss on voting day.

• How to watch, listen to the final Ontario leaders' debate

With the political tables turned so dramatically,Sundayevening's debate the lastbeforethe polls open onJune 7 has the potential to be an exciting 90 minutes that could help decide who will be the next premier of Ontario.

"I don't think I've seen this much momentum behind a candidate in a major election campaign, well, ever," said EKOS Research president Frank Graves, of the NDP'sleap forward in opinion polls.

Horwath: Confident or defensive?

Horwath's lead in the polls, however slight,could give her confidence, said Graves. "Maybe she's thinking, 'I'm on fire!'"

But it won't be easy going. In the earlier debate,Horwathwas seenas a benign third-placer. Now, she will be the target of both Liberal Leader Kathleen Wynne and Progressive Conservative Leader Doug Ford.

Wynnewill undoubtedly bring up the NDP'splatform calculationerror that led to the party's proposed deficit being understated by $1.4 billion.

• VOTE COMPASS | Compare your views to the party platforms

The PCs have spent the past week exposing and criticizing questionable comments of a number of NDP candidates. One of the most recent controversies was an NDP candidate in Toronto who had posted a meme of Hitler on her Facebook page. (The candidate says she has no idea how the meme got there.)

ExpectFord to go afterHorwathover the selection of thesecandidates, slamming theNDPleader for not dismissing them or denouncing some of their past statements more forcefully.

Both strategies will aim to show thatHorwathand theNDParen't ready, or shouldn't be trusted, to take the helm of the province. Horwathcould be spending a fair amount of time on the defensive. She needs toremind people of why they were drawn to her, but also convince them that she will be able to handle the role of premier.

Ford: Needs to look 'premier ready'

Although Ford will likely bring up the Hitler-meme NDP candidate, he'll be skating on pretty thin ice when it comes to criticizing other parties' candidates. One of his candidates in Brampton was forced to resign over his alleged links to stolen data from the company that overseesHighway 407, and there are further accusations that a number of PC candidates may have used that data to help win their nominations. Elections Ontario is investigating.

Just days ago, the Liberals released an audio tape that featuresFord allegedly offering to buy people's party memberships tosecure the PC nomination of his preferred candidate in his home riding of Etobicoke Centre.

• ONTARIO VOTES | Catch up on CBC's complete election coverage

And while Ford has vowed to release a fully costed PC platform, there is no sign of it with less than two weeks until voting day. The cost of his promises have outweighed his unspecified plans to find "efficiencies" which the other two leaders will characterize as cuts to core services.

"Doug Ford needs to somehow figure out a strategy for stopping the cratering of his support," said IhorKorbabiczof AbacusData.

Graves is even more blunt: "He needs to look premier ready."

That won't be easy, with the allegations against him and his party that Wynne andHorwathare likely to come back to again and again.

In the first debate, Ford merely needed to reassure. This time around, he has to win back the support he's lost.

Wynne: A chance to reconnect?

After winning a surprise majority in the last election, Wynne is trailing far behind in the polls. She's got nothing to lose in this debate, which may be to her advantage. She's by far the best speaker of the three leaders, which will come in handy when the debate gets heated.

"It might be fun being Kathleen Wynne in this debate, even if it hasn't been fun being Kathleen Wynne in this campaign," saidKorbabicz.

• POLL TRACKER |Get the latest Ontario projections here

After being criticized in the first debate for delving too deeplyinto policyon occasion, Wynnewill likely divide her time between trying to show why her opponents are not fit to govern and reintroducingher plan to help the people of Ontario.

Butaccording to a member of her team, don't expect any potshots from the Liberal leader. She's planning to take the high road even if Ford mentions her smile again to reconnect with anxious voters.

But with previous surveys showing that more than three-quarters of voters wanta change, it's unclear whether this debate offers a real chanceto convince jadedOntarians to reconsider the Liberals.

• Vote Compass | See how your views compare to the party platforms