
The party has a new deputy leader, Brooke Van Velden, who replaces Beth Houlbrooke, and will take the No 2 spot behind Seymour.
McKee is a first time candidate, while Van Velden stood for Act in Auckalnd Central last election.
On current polling, Seymour would be joined to two or three more Act MPs.

Seymour said Brooke van Velden was qualified in international trade.
Her private sector experience as a corporate affairs consultant and political experience at Parliament had given her a deep understanding of the economy and the effect big government policies and rushed laws have on businesses and individuals.
Van Velden said she switched from being a Green Party voter to an Act supporter while studying economics and international trade at Auckland University.
"The ability for free markets to lift countries from hardship was a revelation for me."

She had a background in law, firearms component imports, was the co-ordinator of the nation's volunteer firearms safety instructors for the Mountain Safety Council as well as being the spokesperson for the Council of Licenced Firearms Owners and its Fair and Reasonable Campaign.
McKee said she would be campaigning to raise Act's Party vote in Rongotai.
"I do not believe that emotive and rushed legislation that adversely affects those it is intended to support is viable.
"Our laws should be rooted in policies that recognise our democratic rights to think, to speak and to behave in a legal and unobstructed way."
Act president Tim Jago said the calibre and experience of candidates would imporess people from every persuasion.
"We have candidates from all walks of life - people who have built their homes, families and businesses and who want to protect and enhance our free society. Our candidates will bring a strong dose of common sense to Parliament," he said.
Among the candidates were End of Life Choice advocates, a former police officer, two teachers, two lawyers, three farmers, four engineers, eleven business owners, and 13 licensed firearms owners.
The full list, of which only 20 are ranked:
1 - David Seymour
2 - Brooke Van Velden
3 - Nicole McKee
4 - Chris Baillie
5 - Simon Court
6 - James McDowall
7 - Karen Chhour
8 - Mark Cameron
9 - Stephen Berry
10 - Toni Severin
11 - Damien Smith
12 - Miles McConway
13 - Beth Houlbrooke
14 - Carmel Claridge
15 - Bruce Carley
16 - Cameron Luxton
17 - Grae O'Sullivan
18 - Myah Deedman
19 - David Seymour
20 - David King
Richard Evans
Robert Andrews
Stu Armstrong
Sean Beamish
Shawn Blanchfield
Kartini Clarke
Jan Daffern
James Davies
Tommy Fergusson
Sean Fitzpatrick
David Fox
David Freeman
Paul Gilbert
Paul Grace
Wayne Grattan
Roger Greenslade
Abby Johnson
Chris Johnston
Judith Kendall
Pete Kirkwood
Niko Kloeten
Tim Kronfeld
Mike McCormick
Brent Miles
Michael Nees
David Olsen
Grae O'Sullivan
Andy Parkins
Matthew Percival
Jack Phillips
Callum Steele-Macintosh
Basil Walker
Blake Webb
Roger Weldon
Bruce Whitehead
Neil Wilson
Ada Xiao