The debate will be livestreamed on the NZ Herald website from 5.30pm.
The event will be moderated by Wellington issues journalist Georgina Campbell. She will ask the candidates the tough questions about transport, climate change, commercial rates, and Three Waters.
Wellington Chamber of Commerce chief executive Simon Arcus said Wellington was at a turning point.
"There is a real need for action in the business community to make sure that we are facing the future in the right way, that we've got the right settings, and that the city is in good form."