It came as senior Liberal sources confirmed the party will direct voters to preference the Greens behind the ALP in the seat. It followed a decision before the 2010 election to direct preference to the Greens, ensuring Labor lost the left-leaning electorate for the first time in more than a century.

Adam Bandt. Credit:Alex Ellinghausen

''There are processes to go through over the next week or so, but I can confirm we won't be directing preferences to the Greens ahead of Labor in Melbourne,'' the source said. ''It will be very, very difficult for the Greens to get across the line because of this.''

The results are at odds with a recent Galaxy poll, also taken towards the end of last month. It found the Greens' primary vote had surged from 36 per cent at the 2010 election to 48 per cent. It put Ms Bowtell on just 29 per cent, finding 21 per cent support for the Liberals. Those results raised the prospect Mr Bandt could get enough votes to win power in his own right without the need for preferences.

In a letter to supporters, Mr Bandt predicted he was ''poised to hold Melbourne with a giant vote of 48 per cent'', although he warned the Greens vote could drop in the final weeks of the campaign ''as the old parties dominate the airwaves''.