The ACT Party has selected one of its existing MPs to contest the upcoming Hamilton West by-election.
James McDowall, who is currently ranked sixth on the party list, was selected from a shortlist of three.
A party spokesperson told RNZ the board was unanimous in its decision.
"It's clear to me that Hamilton West faces some real challenges at the moment, particularly with rising, violent crime, the increasing cost of living and the co-governance of everything," McDowall said.
He planned on campaigning on ACT's policies of introducing ankle bracelets for serious and violent youth offenders, tax relief, and a referendum on co-governance.
"I'm thrilled James is taking on this challenge for the ACT Party. In his short time in Parliament so far James has excelled in taking on the government and proposing new ideas," ACT leader David Seymour said.
McDowall stood in the Waikato electorate in 2020, placing third with 2084 votes, or 5.19 percent, but came into Parliament on the party list.
A spokesperson said ACT's 2020 Hamilton West candidate Roger Weldon would have an active role in McDowall's campaign.
If McDowall wins the by-election, ACT would be able to bring in another MP to Parliament, likely to be Christchurch-based Miles McConway, who is ranked next on the list.
The Hamilton West seat is vacant following the resignation of Dr Gaurav Sharma, who intends to re-contest the seat as an independent candidate.
Also on Thursday, the Aotearoa Legalise Cannabis Party announced recent Christchurch mayoral candidate Peter Wakeman would run for the seat.
The party said Wakeman was a non-smoker of cannabis, and the only high he had experienced was "when he was working as a pilot flying passenger jet aircraft."
Labour has selected Georgie Dansey as its candidate, while Naomi Pocock will represent the Opportunities Party.
National is set to decide between its three-person shortlist of Tama Potaka, Frances Hughes, and Rachel Afeaki-Taumoepeau on Sunday.
New Zealand First has decided not to field a candidate, with leader Winston Peters describing the by-election as "unnecessary" and instead wanting to focus resources on next year's general election. The Green Party is also not contesting the by-election.
Candidate nominations close on 8 November at noon.
The Hamilton West by-election will take place 10 December.