The National Party has risen in popularity following a big-spending Budget which included tax cuts for some families.
The latest TVNZ Colmar-Brunton poll shows National would be able to form a government with the help of two out of three of its support partners.
It rose 3 percentage points to 49 per cent in the poll, giving it 59 seats in the House - just two seats short of a majority.
Labour remained steady on 30 per cent, while its Memorandum of Understanding partner the Green Party fell 2 points to 9 per cent.
New Zealand First rose 1 point to 9 per cent. That meant the Opposition bloc of Labour, the Greens, and NZ First would get 59 seats - not enough to form a Government.
The poll also showed The Opportunities Party (TOP) registering for the first time, getting 1 per cent of the vote. It has recently announced its first candidates for the election, and announced a policy to legalise cannabis.
Of National's support partners, the Maori Party fell 3 points to 1 per cent, while Act's support remained steady on 1 per cent. United Future did not register.
The poll was taken after National released a Budget featuring a $2 billion families package, which cut taxes for some families and boosted the accommodation supplement and Working for Families payments.
In response, Labour and the Greens were not united in opposition. The Greens voted for the Budget bill in the House because it increased payments to low income families while Labour voted against it, saying it could not support legislation which gave bigger tax cuts to higher earners than the poorest families.
The poll of 1000 people had a margin of error of 3.1 per cent.