I decided to retire, not Andrew Little - Annette King

What next for Annette King?

The long-time Labour MP called time on her political career on Wednesday, endorsing new Mt Albert MP Jacinda Ardern as her replacement as deputy.

"Nobody within our caucus or the party was saying I should go, but the commentators then decided I should go, then started to put questions to me as to why didn't I go," she told The AM Show on Thursday.

"You know me - nobody's going to tell me what I'm going to do, I'll make my own decisions, which I did."

What isn't decided is what she'll do next. Whatever it is, her husband will have to approve.

"Seventeen years he's put up with me, walking behind me, carrying the handbag, having to be the politician's husband - and now it's his turn."

Though she turns 70 just before this year's general election, Ms King doesn't intend to retire quietly.

Regularly appearing on The AM Show and its predecessor Paul Henry alongside friend and rival Judith Collins, Ms King says the odd couple could perhaps start their own show. Or perhaps more realistically, she'll seek a new role in the public service.

"I had so many portfolios over my life - from health to police, to transport, to state services and justice, there are roles I could play."

No regrets

As recently as Sunday, Labour leader Andrew Little said there was "no vacancy" in the party's leadership team. On Monday, Ms Ardern told The AM Show she wouldn't stand even if the rest of the Labour caucus was wiped out by a bus.

"I believe Jacinda is ready for the role," said Ms King, endorsing a woman half her age - despite previously rubbishing speculation Ms Ardern would replace her as "ageist".

"Nobody's bullied me at all. I've made my own decision. I went in there and I told [Mr Little] I'd stand down as deputy.

"I have to say I've been thinking about it for a while... it wasn't a surprise. When Andrew was saying there's no vacancy, that's true - there was only ever a vacancy if I stepped out of the role or the caucus kicked me out of the role. It wasn't a decision he could make."

In Ms King's time in Parliament, she's fought 10 elections and served under eight leaders - David Lange, Geoffrey Palmer, Mike Moore, Helen Clark, Phil Goff, David Shearer, David Cunliffe and Mr Little. That's half the leaders the party, founded in 1916, has ever had.

"I've done my time, and I've enjoyed every minute of it."