The leaders of Quebec's four main political parties will face off tonight in the last debate before voters go to the polls on April 7.

The event will be broadcast live from 8 p.m. to 10 p.m. ET on TVA, LCN and Argent.

The debate is divided into three themes: social policies and governance, economy and public finances, identity and sovereignty.

The four candidates are Liberal Leader Philippe Couillard, Québec Solidaire co-spokesperson Françoise David, Coalition Avenir Québec Leader François Legault and Parti Québécois Leader Pauline Marois.

They will have the opportunity to face off one-on-one for each of the themes, and then face off again in a four-person debate.

Here's what you should watch for tonight:

1. Integrity

A new issue to emerge in the campaign this week, as both leading parties are spattered with questions and allegations in the last 48 hours. 

Who can make the stronger case in the debate on issues of integrity?

2. Referendum

A significant discussion in this campaign, this final leaders debate could be key for voters who are trying to decide how they feel about a referendum on Quebec's independence. How will candidates keep it at the forefront or quell the conversation? 

3. CAQ lures votes

François Legault needs to convince supporters who drifted to the Liberals to come back to the Coalition Avenir Québec. He'll have to do so by convincing them they don't have to worry about a PQ majority anymore.

4. The left

Can Québec Solidaire co-spokesperson Françoise David continue to draw left-wing voters who are turned off by the PQ's apparent shift to the right? She'll work to solidify her party's position as a true left party and one that is a viable option for voters. Pauline Marois needs to paint the increasingly popular Québec Solidaire as a fringe group who will never be able to govern.

5. Overall impressions

Overall impressions play a big role in determining influences on voters. Philippe Couillard needs to show he can be premier, while Marois, who seemed to struggle with composure during the last debate, needs to reassure voters she's capable of leading a majority government.