Taken between Thursday and Monday, the poll found that Labor's Cath Bowtell might struggle to get home even with the help of Liberal preferences because of a collapsing Labor vote, a rising Liberal vote, and what appears a very high leakage rate of Liberal second-preference votes to the Greens.

Asked who they would vote for first and which party would get their second preference, just half of the 26 per cent of voters who backed the Liberal Party said they would send their second preference Labor's way.

Forty per cent said they would rather support Mr Bandt than see their vote go to elect Ms Bowtell.

Based on the stated preferences of respondents, that translates to a two-party-preferred vote in favour of Mr Bandt of 54 per cent to Labor's 46 per cent - only a two-point drop in the Greens vote since 2010 despite the Liberal deal.

Primary voting intentions revealed in the poll show Ms Bowtell stands on just 30 per cent in the once-safe Labor stronghold, down eight points from the 2010 election. The Liberal vote is up 4.5 points at 26 per cent, and the Greens are up 4.5 points at 40 per cent.