However, Prime Minister Jacinda Ardern has lost a quarter of her support as prime minister in a rapid softening of her personal fandom.

TVNZ's poll released on Monday showed that if an election was held over the last week, Labour would retain its majority in parliament.

Labour polled 49 per cent, down four from the last poll in December, which would give it 62 seats in the 120-member house.

"That's steady support and I take great heart from that," Ms Ardern said.

Ms Ardern downplayed a drop in support for her as preferred prime minister dropped from 58 per cent to 43 per cent.

"I dont spend too much time analysing those numbers for me personally," she said.

In any case, Ms Ardern can sleep easy with her parliamentary majority, her crushing lead over opposition party National, and the next election not being due for two and a half years.

Opposition National is up two from December but remains at sea, and a long way from power, on 27 per cent.

Opposition leader Judith Collins is also streets from being the nation's preferred leader, polling eight per cent, down four.

TVNZ political editor Jessica Mutch-McKay said pressure would come on Ms Collins to improve National's polling fortunes - but she was likely safe in the job for the rest of the year.

Australian Associated Press