Labour MP Jacinda Ardern has spoken publicly about Graham Lowe's description of her as a "pretty little thing" for the first time, saying it was "frustrating" to be judged on issues such as how she did her hair rather than her work.

Mr Lowe had described her as "a pretty little thing" on Paul Henry's TV3 breakfast show the morning after a Herald DigiPoll survey showed a boost of support for Ms Ardern as preferred Prime Minister and a future Labour leader.

Ms Ardern had refused to comment at the time, but told TVNZ's Q+A on Sunday that she doubted Mr Lowe meant to offend her.

"But some of the commentary that occurred afterwards, some of that I found very hard to read. And I do find it frustrating. I got into politics to make a difference and I want people to scrutinise my ideas, the alternatives I put up, not whether or not my hair means I'm not credible enough to do the job."


She said she had hoped people did not believe that someone who was well presented could not be a serious politician.

"But some of the commentary I saw did make me question whether or not that was front of peoples' minds."

She said she was talking openly about it because she did not want other young women interested in a political career to think it was an every day occurrence to be targeted for their looks.

"They don't. I don't. This is a some of the time issue."

Ms Ardern also responded to criticism in the wake of Mr Lowe's comment that she had done little of real substance as an MP, saying success was not only measured by the 'scalps' politicians got.

She said her measure of success was in holding the government to account, creating new ideas and advocating for those she represented, especially in the area of child poverty.

She said it had never made her question doing the job.

"These kind of comments, I never let get to me to the point I would consider leaving this opportunity."

She defended her decision to do interviews in 'soft' media, such as women's magazines, saying most people did not watch Parliament TV and it allowed her to take a message on issues such as child poverty to a wider audience.

Ms Ardern also said she had no desire to be Labour leader, despite the polling. She said people assumed everybody who went into politics wanted to be Prime Minister but in her case it was not true.

"That's never been my aspiration since being in Parliament."

She said she did hope to be a minister one day, but as a former staffer to Helen Clark had seen what it took to be Prime Minister.

"When I say that, you know, I actually say it with a tiny bit of selfishness. I love the job that I'm privileged enough to do and the opportunities I have to make change are fantastic, once in a lifetime opportunities. But I also like the ability to spend a bit of time with my family, and with my friends and have just that little bit of balance."

In the last Herald DigiPoll survey, Ms Ardern got 3.9 per cent as preferred Prime Minister, up from her usual 0.5 per cent.

She was the most popular Labour MP after leader Andrew Little in that poll. She also got 20 per cent support in a separate question about who should succeed Andrew Little - just behind deputy Annette King and ahead of former leadership contender Grant Robertson.

Ardern has run on a 'ticket' as former leadership contender Grant Robertson's deputy in the past and is likely to be in the running as Mr Little's deputy when he does his reshuffle later this year. Annette King was installed a deputy to bed in the rookie Little but he said at the time that was for a year.