Key Points:

New Auckland Central MP Nikki Kaye has singled out home affordability for young families and the environment as key areas to focus on in Parliament.

Ms Kaye is celebrating taking Auckland Central from Labour's Judith Tizard - the first time National has captured the inner city seat.

Ms Kaye, a 28-year-old businesswoman and relative newcomer to politics, has a 1,261 vote majority over Ms Tizard, who has been a part of inner Labour party circles in Auckland for decades, had held the seat since 1999 and was the unofficial "Minister for Auckland".

More worryingly for Labour, National won the party vote by an even bigger margin - 1500 votes - in the seat which contains a mix of inner city flats, liberal voters, suburban areas and areas like Ponsonby with high-income families in high worth homes.

In interviews today, Ms Kaye said that 60 per cent of her electorate was aged under 40.

Many of them had worries with the rising cost of houses and the debt burden of ballooning mortgages

Speaking to Kerre Woodham on Newstalk ZB this morning, Ms Kaye said she would champion home affordability, the environment and small business concerns in Parliament.

Campaigning on Waiheke Island and other islands of the Hauraki Gulf, she had discussed the need for more marine reserves.

"Auckland Central is also a seat filled with creative small business people. Working on ways to help small businesses will be a big priority."

Asked if environmental and housing issues were normal National areas of concern, Ms Kaye said they were of vital interest to her constituents.

"I'm a National member because I really believe in the equality of opportunity for all, not the equality of outcome."

She said that was looking forward to the challenge and also working with new National MPs like Simon Bridges, who has held Tauranga for National with the retirement of Bob Clarkson, holding off a challenge from NZ First leader Winston Peters.

Ousted MP Ms Tizard said she was philosophical about losing her seat.

Ms Tizard said having been MP since 1990, she had had some fantastic opportunities. She said she had access to a large range of people locally and internationally.

The longtime MP said she had done all she could, and now it was somebody else's turn.

She said it was an extraordinary honour and privilege to represent the public.

"I'm looking at my somewhat chaotic garden thinking, you know, this is the first time in 18 years I'll be able to get in and do some serious gardening. I mean I think I just need to stop and think."

Ms Tizard, who has been a confidant of former Prime Minister Helen Clark, said Helen Clark mentioned nothing to her about leaving Labour's top job.

Ms Tizard says the decision was an honourable one, and Helen Clark would go down as one of New Zealand's greatest prime ministers.