New Zealand PM Ardern under fire as minister quits

New Zealand's Prime Minister Jacinda Ardern has been beset by policy squabbles with coalition partners and plummeting business confidence

New Zealand Prime Minister Jacinda Ardern faced her first major crisis Friday over her handling of a gaffe-prone minister's resignation.

Ardern swept to power on a wave of "Jacinda-mania" late last year, with her centre-left Labour Party leading a coalition that promised "a government of change".

The optimism surrounding her administration was enhanced in June when she gave birth to daughter Neve -- becoming only the second female leader in the world to have a baby in office.

But the lustre surrounding the 38-year-old has dimmed in recent weeks amid policy squabbles with coalition partners and plummeting business confidence.

Ardern revealed Friday that her government had suffered its first casualty, with Broadcasting Minister Clare Curran resigning after using a private email account to conduct government business.

Curran, who had been disciplined twice previously for failing to declare meetings, said she faced "intolerable pressure" and did not want to become a distraction for the government.

But it was the way Ardern dealt with the problem that drew most criticism, with opponents accusing her of misleading the public.

Asked on talkback radio on Friday morning whether she was considering firing Curran, she replied: "No, I think she's paid her price.

"We want to make sure that you don't set the bar so high that you have a situation where you show a bit of human frailty and you lose your job over it."

In fact, Ardern had accepted Curran's resignation the previous night but failed to mention it during the 10-minute interview.

Ardern later insisted that she answered the question correctly but opposition leader Simon Bridges zeroed in on her evasiveness, saying she had mishandled the affair.

"The prime minister needs to explain why she misled New Zealanders this morning by saying Ms Curran's job was safe when Ms Curran says she resigned last night," he said.

"This whole saga has seriously damaged the credibility of both the prime minister and the government."

Another of Ardern's ministers, Meka Whaitiri, has stood aside from her customs portfolio while under investigation for an alleged physical altercation with a staffer.

Meanwhile coalition partner New Zealand First, led by populist veteran Winston Peters, has undermined her election pledge to lift New Zealand's refugee quota.

Ardern also came under fire this week for arriving late at a Pacific summit in Nauru to minimise time away from her baby, although defenders labelled such criticism petty and overly partisan.