National has maintained a high poll rating and could govern without partners on 49.7 per cent in the latest TV3 Reid Research poll.
National would have 64 seats in a 121-seat Parliament.
Labour has slipped by 2.2 points 27.3 per cent.
The combined left bloc of Labour, the Greens and Internet-Mana would be 53 seats, 15 fewer seats than the combined bloc of National and its current partners of Act, United and the Maori Party, 68 in total, assuming each of the partners keeps an electorate seat.
Internet Mana polled 1.8 per cent. Assuming Mana leader Hone Harawira keeps Te Tai Tokerau, he would bring in Internet leader Laila Harre.