Labour MP Ruth Dyson has announced she won't seek re-election as the Labour candidate for Port Hills in 2020.
The former Labour Party president says she's stepping away from Parliament to "pursue other challenges", but hasn't yet determined what those challenges will be.
Ms Dyson says she'll be leaving the job on a high.
"This has not been an easy decision to make but it is one that has been made considerably easier by the fact that I am leaving at a time when Labour is strong and united, with a clear plan to deliver the policies that I have worked hard to develop," she said in a statement to media.
"I don't recall a time when Labour has been more united as a team or when we have had such an amazing recruitment of new activists. It's a great time to be Labour!"
Prime Minister Jacinda Ardern hailed Ms Dyson as a "loyal member and outstanding contributor to the Labour family".
"As President, MP, Minister and Whip, she has held just about every major role in the party. She is smart, generous and kind. We are going to miss her," she said.
"As with her entire political career she will go out in her own way, well signalled and planned and achieving that rare thing in politics where your leaving is of your own choosing."
Ms Dyson will be staying in her role until the election next year. She's adamant there are no "undisclosed" reasons for her leaving her role, saying "it's just the right time".