All polls currently suggest the Australian Greens are on track to record their highest ever vote on 21 August. The Greens are almost certain to hold the balance of power in the Senate from 1 July 2011.

In a two-part piece, Crikey looks at the party poised to become Australia’s third political force.

In 2007, the Greens attracted 7.8% of the national vote in the House of Representatives and just over 9% in the Senate. They performed most strongly in Tasmania and the ACT. Their best effort in a major state was just over 10% in the Senate in Victoria.

The current polling suggests the Greens are poised to improve on that result. Newspoll says the Greens’ current level of support is 12%; Nielsen 12%; Essential 13%; Galaxy 13%. The Morgan poll, which was the first to pick up the slow rise of the Green vote last year, has them currently sitting on 10.5%.

Newspoll, Nielsen and Essential and, to a lesser extent Morgan, all tell the same story: the Greens vote peaked in the polls in early-mid June as Labor’s primary vote collapsed, but fell back as voters returned to Labor before and after the removal of Kevin Rudd. That fall appears to have stabilized just before the calling of the election, leaving the Greens with a significantly higher level of support than in 2009.

Much of the rise has been attributed to disgruntled left-wing Labor voters switching to the Greens out of disillusion with, first, the Rudd Government’s disappointing CPRS, and later its shift to the right on asylum seekers. Essential Research polling found the Green vote to be significantly softer than that of the major parties, an impression confirmed when the Greens’ peak — at one stage in Newspoll they reached the dizzying height of 16% — passed and much of that support returned to Labor.

Even so, as we close in on 21 August, Greens support is sitting well above levels recorded at the last election.

Whether that polling position translates into a similar performance on 21 August, however, must be doubted. As Antony Green has noted, now that the Greens are being separately identified in pollsters’ questions, polling may well overestimate the Greens’ support, when previously it had underestimated it. And the Greens, like all smaller parties, will struggle for coverage now that the campaign has started as the media concentrates on the presidential-style campaigns of Labor and the Liberals.

The Greens will be also heavily outspent by the major parties in advertising during the campaign, although the disparity is unlikely to be as great as in 2007, when Labor and Liberal hurled $40m worth of advertising at each other. The 2010 campaign is a decidedly leaner affair.

Financially, the Greens are far more reliant on their party membership than the major parties. They claim to have “around 10,000 members”. By some estimates that’s around a quarter of the major parties. Others say the jealously-guarded membership number of the Labor and Liberal parties are much lower, particularly when it comes to active members. The Greens almost certainly have a far younger membership as well, with both major parties and especially the Liberals carrying a lot of retirees in their branches. Last election year, 2007-08, the Greens only earned $1.1m, including over $640,000 in membership fees and state contributions.

The party garnered less than $300,000 in donations. However, they recouped over $4m in electoral funding. This, Bob Brown noted in a plea for more federal donations earlier this year, had almost entirely been returned to the party’s state branches.

Greens candidates still reflect the party’s traditional base in the public sector. Teachers, both secondary and tertiary, are the largest occupation among Greens House of Representatives candidates this year. Doctors, lawyers and social workers and community activists are also well-represented. A number of local councilors are also standing for the Greens, who can now draw on representation at all levels of government and in all states except Queensland. There are 22 state Greens MPs – although they are all upper house representatives or in electorates with forms of proportional representation, like the ACT and Tasmania. It’s no coincidence that those are the two jurisdictions where the Greens hold the balance of power.

However, the Greens have been more successful in NSW and Victoria at local level, with more than 80 Greens local councilors in those states — although primarily in inner urban areas. There are over 100 Greens at local government level throughout the country. The party has, within limited areas, developed a significant presence within Parliaments and council chambers.

Tomorrow: the Greens most likely to enter Federal politics on 21 August…