Disaffected wave could unseat ministers

THE surge in support for the Greens could unseat two prominent ministers and double the party's numbers in the Senate if it can be sustained to election day, analysis by The Age shows.

The latest readings from the four established polls The Age/Nielsen poll, Galaxy, Morgan and Newspoll on average show there has been a swing of 5 per cent in first preferences from Labor to the Greens since the 2007 election.

This means that one in every eight people who voted Labor in 2007 now say they would vote for the Greens. That has lifted the Greens from 7.8 per cent to 13 per cent their highest rating ever.

On these figures, the Greens stand to defeat Finance Minister Lindsay Tanner in his seat of Melbourne, which he held in 2007 by just 4.7 per cent when the Greens beat the Liberals into third place.

Housing Minister Tanya Plibersek could also lose her seat of Sydney, where the Greens need a 5 per cent swing.

The Greens also have a realistic chance in the inner-Hobart seat of Denison, where former Attorney-General Duncan Kerr is retiring. To win any other seats in the lower house, they would need swings of at least 10 per cent.

To have a realistic chance of winning any lower house seat, however, the Greens would have to match this level of support when Australians are in the polling booths.

Third parties often win in the polls, but lose in the booths. Six months before an election is the time most people express discontent with sitting governments. By election day, they usually do better than polls suggested they would, as voters are bombarded with well-targeted handouts and campaign messages, and recoil from the alternatives.

In 2001 and 2004, John Howard was behind at this stage, then surged home to win.

But with the Greens joining Labor in a coalition in Tasmania, and the example set by Liberal Democrats teaming up with the Conservatives to form a centre-right government in Britain, this election looms as the Greens' chance to make a breakthrough at federal level.

With the polls showing voters split 50-50 between Labor and the Coalition after preferences, a Greens win in any seat could see it share the balance of power in a hung Parliament as well as in the Senate.

If current polling was repeated on election day, the Greens would double their Senate seats, going from five seats now, to 10.

In the 76-member senate, they would have the balance of power to themselves.

They could pick up Senate seats from Labor in New South Wales and South Australia, from the Coalition in Queensland and Tasmania, while in Victoria, medico and perennial Greens candidate Richard di Natale would unseat Family First leader Steve Fielding.

At the 2007 election, the Greens narrowly lost the final seats in three states: by 0.4 per cent in Victoria, by 0.7 per cent in Queensland, and by 1.6 per cent in New South Wales. Senate elections are dangerous to call, but they are odds-on to win the balance of power, at least.

By contrast, there has been no gain since 2007 in the Coalition's primary vote. It has gained about 2.5 per cent in two-party preferred terms, but entirely due to votes shifting from Labor via the Greens, smaller parties and independents.