Dumped New Zealand First MP Andrew Williams is seeking a judicial review to challenge his axing from the party list, which he says breached a requirement for fair treatment.
In a statement released this afternoon, Mr Williams said his legal team would file papers in the Auckland High Court today seeking declarations that the party breached its constitution when it dumped him as an electorate and list candidate.
"I regret that I have no other option other than to take my party to court to protect my reputation", Mr Williams said.
"The manner in which I have been mistreated by the party has forced me to seek court declarations that the revocation of my electorate and list candidacies, and my removal from the party list, breached the processes in the party's constitution for fair treatment.
"There are numerous protections in the New Zealand First Constitution to ensure fair treatment, which I have not been accorded.
This includes not being given an opportunity to respond to the decision to remove me from the party list."
Mr Williams was understood to have firstly been demoted to number 13 on the party's draft list. He subsequently blamed the demotion on deputy leader Tracey Martin, who he said was trying to remove him because she was threatened by him.
Mr Williams was dumped from the official party list, released this week.
"I remain committed to the ideals which New Zealand First represents," Mr Williams said.
"Recognised as a competent New Zealand First MP, ranked at number 3 in the party, I was given no reason for my demotion to 13th place.
"I do not, however, wish to derail NZ First's campaign, so I am asking for an urgent hearing following the election. As the matter is now before the Court, I do not intend to make further comment."
New Zealand First leader Winston Peters did not immediately respond to requests for comment.
Deputy leader Tracey Martin did not want to comment on whether Mr Williams was fairly treated.
"I'm not going to going to comment on whether it's fair or unfair. The process is the process, and we've got a list, and I'm going to spend the next 23 days campaigning for New Zealand First."