Newshub poll: Jacinda Ardern preferred as PM over Andrew Little

Labour's secret weapon and superstar Jacinda Ardern has already leapfrogged her leader in the popularity contest.

The latest Newshub Reid Research poll has deputy leader Ms Ardern on 10.5 percent in the preferred Prime Minister stakes, more than 2 points higher than leader Andrew Little, who is on 8.3 percent.

Mr Little isn't shaken by his deputy's meteoric rise, saying he's not threatened or intimidated by her blossoming appeal with voters. 

"It doesn't scare me. It doesn't make me feel awkward," he told Newshub.

"I'm very pleased we have a deputy leader who is as popular as she is."

Newshub poll: Jacinda Ardern preferred as PM over Andrew Little

Prime Minister Bill English came out on top of the pack in the preferred Prime Minister rankings with 25 percent, but that's a slide of more than 11 percent from John Key's 36.7 percent in August 2016, his lowest in eight years.

Not only was Mr Little beaten by Ms Ardern, he was pipped by NZ First leader Winston Peters too, who came in third with 8.9 percent.

Ms Ardern has only been in the deputy seat for two weeks - this is the first poll since her promotion.

But her popularity hasn't had as much of an effect on the party vote - National is up two points to 47.1 percent, while Labour is down by the same to 31 percent.

The Greens are also down 0.3 points to 11.3 percent - that makes the Labour/Green total 42.3 percent, which is not enough to govern.

New Zealand First came in on 7.6 percent - down half a point from the last poll.

Newshub poll: Jacinda Ardern preferred as PM over Andrew Little

Based on the party vote figures, Parliament would be tied and Mr Peters would be needed to break the tie. Newshub approached him about it, but he didn't want to talk.

"Your polls are absolute drivel," was his response.

The Newshub-Reid Research poll was conducted March 10-19. 1000 people were surveyed, 750 by telephone and 250 by internet panel. It has a margin of error of 3.1%.