Tonight Bill English and Jacinda Ardern go head-to-head in front of a live audience of hundreds of undecided voters, with countless more watching from their living rooms.
And there’s one thing that should be on the leaders' minds: early voters.
This is the last major televised debate before advance voting opens on September 11.
Early voting, or casting ballots before election day, will be vital element in this campaign.
At the 2008 election, about one in 10 voters cast an early ballot. In 2011 it was 15 percent and at the last election it was 30 percent.
The Electoral Commission says as many as 50 percent of all voters could cast advance ballots this election.
That's huge. It means the leaders have just one week to get their message to half of the voting population who start voting next Monday.
Jacinda Ardern and Bill English can’t say "we've got a few weeks to convince voters to back us".
With just seven days to go, they must make their big pitch tonight.
It's do or die time.