The National Party has opened up a 30 point lead over the Labour Party in the latest TV3 poll released on Sunday.
The preferred party poll puts National up almost 3% to 57.5%, just short of the record high of 60% the party reached two years ago.
While National is up, Labour is down almost four points to 27.1.
That would give National a comfortable majority of 71 seats in the 120-seat Parliament and Labour just 34.
The poll was taken after a difficult few weeks for Labour, which has had to deal with the sudden resignation of MP Darren Hughes, who is under police investigation, and criticism of its party list by senior MP Damien O'Connor.
Both the Green Party and New Zealand First are down 0.5 - with the Greens on 7.7% and New Zealand First on 2.8%.
The Maori Party is up slightly to 2.5% and the ACT Party is up more than 1% to 1.7.
The poll has a margin of error of 3.1 percentage points.