NZ's next PM: Old, new, or wild card?

The contest for New Zealand's next Prime Minister will be between an old hand, a newer face, and a wild card.

Deputy Prime Minister Bill English, Health Minister Jonathan Coleman and Police and and Corrections Minister Judith Collins declared they would stand for the position of National Party leader and Prime Minister yesterday.

Of the other potential candidates, Social Housing Minister Paula Bennett is refusing to rule herself out of the race. Transport Minister Simon Bridges and Justice Minister Amy Adams say they will not stand, but remain in the picture as possible deputies.

The three candidates stated their case for the top job in the country yesterday.

English, an MP of 26 years, said he would focus on regenerating the party and maintaining economic growth. He wanted New Zealanders to see the benefits of that growth, including the country's most vulnerable and disadvantaged.

Outgoing Prime Minister John Key and several other senior ministers have endorsed English, but English said he was not taking a win for granted.

Bennett has been tipped as a possible deputy for English. Neither she nor English would discuss the issue yesterday.

Coleman, in a thinly-veiled shot at English, said there was a "significant appetite" for a "change from the status quo".

In a clear bid to paint himself as the fresh face compared to English, he said he was "relatively young" and although he had been politics for 11 years he was not a "professional politician". There are just four years between English and Coleman.

Coleman would not name a deputy, but spoke warmly about Adams. Adams said she was not attached to any ticket at this point.

Collins is the outsider in the contest. Declaring her bid yesterday, she said National could expect its "toughest challenge ever" at the 2017 election and she was the toughest candidate.

She also underlined her credentials as a woman, saying National had been led by men "for quite some time" and the party needed someone who could appeal to both men and women and all ethnicities. "I believe I can do that," she told reporters.

Her bid immediately raised questions about her controversial past, which has included a conflict of interest scandal involving her husband and allegations she tried to undermine a senior public servant.

An inquiry into the second case found she no evidence of wrong-doing, though she went further yesterday and said she had been "completely exonerated".