Under Simon Bridges, National has nosedived to its worst result in more than a decade.
A Newshub poll showed National only had 41.6 per cent while Labour was on 47.5 per cent.
Polling on the preferred prime minister had Jacinda Ardern far ahead again on 41.8 per cent.
Bridges only had 5 per cent of the vote while Judith Collins overtook him on 6.2 per cent.
New Zealand First would not make it back to parliament with only 2.9 per cent of the vote while the Greens would just scrape through on 5.1 per cent.
This would allow Labour and the Greens to govern alone.
ZB Political Editor Barry Soper told Larry Williams the writing is essentially on the wall.
"That's unsustainable for Simon Bridges, particularly when you see Judith Collins. She's out polling her leader."
Soper says the last time this happened, when a MP outperformed the leader, that was Jacinda Ardern polling higher than Andrew Little.
He doubts that National will wait for another poll to make their mind up.
"They had an opinion poll, that was their internal polling, at their caucus last week. That apparently was still in the 40s, but Simon Bridges' own polling was not shown to his caucus."
Soper says that is rare, as the leader's polls is usually shown to the caucus. He says this also happened at the final caucus meeting last year.
Despite the big jump, but Finance Minister Grant Robertson says it's not being taken lightly.
Robertson says he's encouraged by the result.
"You gotta be careful with the specific numbers and ups and downs of poll, but overall we feel we are focused on the right issues."
Since becoming Prime Minister, Ardern has been way out in front as preferred Prime Minister, although former Prime Minister Bill English rated 25.7 per cent shortly before he resigned as National leader a year ago.
In the more recent 1 News Colmar Brunton poll, Jacinda Ardern was on 39 per cent, Simon Bridges was on 7 per cent , Judith Collins on 6 per cent and Winston Peters on 4 per cent.
Some of the political events that occurred over shortly before or over the polling period included Ardern's trip to London, Davos and Brussels; Bridges' announcement that National would index tax-rate thresholds to inflation; an acknowledgement by the Government that Kiwibuild would fall well short of its short term target; ex-National MP Jami-Lee Ross re-entering public life and Sarah Dowie being named as the ex-lover who sent him a text message saying "you deserve to die" which is being investigated by police.