Longstanding Labour MP Annette King will stand as a list-only candidate in 2017 - a step that opens up her Rongotai seat for Labour leader Andrew Little should he decide to stand there.
King told the Herald that after 24 years she had decided "with some sadness" not to stand in the electorate again in 2017.
She hoped to be health minister in the next Labour government and would stand on the list, but it was possible she would leave if Labour was still in Opposition.
Little, a list MP, has lived in the Rongotai electorate for years and said he would consider standing in the seat.
"Up until now it was an attractive option as leader of the party to remain list because you get drawn all over the country. Being tied to an electorate, particularly if I'm campaigning to win it for the first time, creates an extra workload.
"But given I live in the electorate, I know many of the people, it is at least something I should give consideration to."
There has been ongoing speculation King would step aside to give Little an electorate after his two failed tilts to win New Plymouth. He made it back into Parliament by a narrow margin after 2014.
King, 69, denied her decision was part of any arrangement with Little, saying she simply believed it was time for another generation to take on the electorate.
She did not know if Little wanted to stand there and had made her own decision to step aside.
"Nobody has ever asked me to leave. In fact, the opposite. I'm asked nearly every day 'are you going to stand'."
Little said in National the leader and finance minister were also both now list MPs "and that reflects on a modern MMP environment".
Labour nominations for Rongotai selection close in early February.
Bill English is the first list MP to become prime minister but no elected PM has been a list MP so far. English had represented the Southland electorate for 24 years before deciding to stand on the list only in 2014.
King said she was sad but after 24 years it was time for someone else to take over.
"I'm in the 60s generation, we need somebody in the 40s or round that age. You need somebody that can take on the seat and do it for 20-odd years.
"So it's an end of an era for me. It's been my life for a long time and I feel a bit tearful, but you have to make a decision and I've thought about this and thought about it for a long time.
"It's an absolutely wonderful seat. It's a Wellington one, it's got all the different communities from refugees through to professional people, the film industry, you name it."
King kept her roles as deputy leader and health spokeswoman in Little's reshuffle yesterday.