The latest Nielsen poll in Australia shows Labor is losing support to the Greens with a drop of four points in its primary vote while the Greens gained two points.
The poll, published in the Fairfax press, has Labor's primary support falling to 34% as the Greens rise from 12% to 14%. The Coalition is down one point on 43%.
The two-party preferred vote has the Coalition leading Labor two points at 51% to 49%.
Julia Gillard still leads Tony Abbott as preferred prime minister at 53% to his 39%.
The ABC reports the poll also shows that 46% of people are in favour of a carbon price, with 44% opposed.
Opinion is almost equally split on support for the Afghanistan war.