The Labour Party has overtaken National in the party vote in a sensational new poll.
The 1News Colmar Brunton poll showed Labour had risen 6 points to 43 per cent, while National had fallen three points to 41 per cent.
Labour leader Jacinda Ardern also leads the preferred Prime Minister poll, rising 4 points to 34 per cent. National leader Bill English rose three points to 33 per cent.
NZ First leader Winston fell 3 points to 4 per cent.
Labour could now form a government with just NZ First as a coalition partner. It could not get over the line with just the Greens.
The embattled Greens rose 1 point to make the crucial 5 per cent threshold.
NZ First fell two points to 8 per cent.
The Opportunities Party fell 1 point to 1 per cent, while Maori Party also fell 1 per cent to 1 per cent. No other parties were in the picture.
Labour has now risen 19 points in the four weeks since Ardern took over as leader.
It is the first time Labour has polled higher than National since 2006, when Helen Clark was in charge.
The previous poll in mid-August showed National was on 44 per cent and Labour was on 37 per cent.
National leader Bill English and Jacinda Ardern were neck-and-neck in the preferred Prime Minister stakes in the last poll, on 30 per cent.
In the leadup to the latest poll, Labour officially launched its election campaign at a high-profile event at the Auckland Town Hall.
Ardern has also announced new policies including free tertiary education, cutting GP costs to $8 for half of New Zealanders, and construction of a $1 billion hospital in Dunedin.
National launched its campaign on Sunday, announcing an education package which included funding to allow all schoolchildren to learn a second language, improvements to maths teaching at primary level, and digital learning at secondary schools.
Leader Bill English has also announced four more weeks of paid parental leave and $10.5 billion on seven new highways around New Zealand.
National was also accused by NZ First leader Winston Peters of leaking details about his superannuation payments, though it is not known whether this fell within the polling period.
Labour has risen dramatically in the polls since Ardern became leader four weeks ago.
Before she replaced Andrew Little, Labour's result in the same poll was 24 per cent.