Labour's poll support has slipped after an initial surge following David Cunliffe's election as leader, the latest Herald-DigiPoll survey shows.
The Maori Party would hold the balance of power if the figures were translated to an election result.
With the left and right blocs fairly evenly split, it could be a close election next year.
Neither National nor Labour would be able to form a government without the Maori Party.
Labour has fallen 2.3 points in the survey to 35.4 per cent. In the September poll, it had a surge in support and could have formed a government with just the Greens and Mana.
National has risen 3.1 points and Prime Minister John Key has somewhat recovered in the preferred Prime Minister stakes, after taking a 9.4 point dive in the last poll.
He has jumped 6.1 points to 61.9 per cent, well ahead of Mr Cunliffe on 16.5 per cent.
Mr Key told the Herald last night that it was good to end the year in a strong position. "That reflects the growing economic confidence and the acknowledgement by voters that we've steered the ship on a very deliberate and accurate course to economic prosperity."
He said that strong year-end polls were important to parties "because people go on their summer holidays and over the barbecue they talk about who is likely to win the election and this poll has got to be very good news for National".
Here are the results in graphical form:
After the plethora of asset sales-related
It's an excellent note for National and John Key to finish the year on, but David Cunliffe will be deeply disappointed. As the economy continues to prosper, he has a mountain to climb in 2014.