Prime Minister John Key has conceded National risk losing the election should the Green Party hold the balance of power.
The Green Party captured 10.1 per cent in the latest DigiPoll, the party's highest rating in the poll since the 2002 election campaign. With Labour floundering around the 30 per cent mark in most polls, and no other minor party polling higher than 2 per cent, the Greens could hold the balance of power should National fail to win 50 per cent of the vote.
The Greens have not ruled out working with National, but it's has been described as "unlikely" by the party's leaders.
This morning John Key National leader told TV One's Breakfast the Green Party are a natural partner for Labour.
"I think it is important to understand if the Greens hold the balance of power it would be a Phil Goff Labour-led government and I think they would be quite upfront about that," Mr Key said.