Both established major parties are on the nose. Diving popularity for Abbott and Rudd and a rejection of their parties by nearly one in four voters have led some, including former Democrat leader Natasha Stott-Despoja to muse whether it 'might even be time for a new political party?'

So far however, the Greens have been the beneficiary and are proving more electorally effective than their Democrat predecessors which they replaced on the cross-benches.

The surge in the Green polling to up to 16 per cent, along with the party's recent 20 per cent record in the Tasmanian election, shows that criticism suggesting the party would be unable to attract a broad base of support has proven to be unfounded.

As a former national president of the Australian Democrats, I was among such critics, arguing that the Greens would struggle to replace the Democrats in pulling enough votes from both major parties to threaten the two-party system. I was wrong, and the proof is not just in the polling but the election results.

The Greens are already surpassing the electoral achievements of the Democrats by entering into a coalition government in Tasmania, and are serious contenders on current polling to win a senator in every state and even seats and the possible balance of power in the House of Representatives.

These are achievements the Australian Democrats, for all their legislative work in the Senate, never made in 30 years - and the Greens have reached this point in half the time.

Critics of the Greens have pointed to perceptions of the party as 'too radical' and 'left of Labor' to attract a broad coalition of voters disaffected by the major parties. The successful if nonetheless misleading campaigns run by the Herald Sun and Family First tarred the Greens with being radical on drugs policy, or 'Watermelons' who were 'green on the outside and red inside'.

Scare campaigns can work against the unknown, but the ongoing success and proliferation of Greens representatives in local government as well as local campaigns mean that less of this will stick over time.

The Greens risk is not radicalism, but timidity. Far from being radical, Greens representatives have been remarkably centrist in their politics. In terms of the perception of the party as being a collection of 'radical greenies', the firm foundation of the party and identification with environmentalism has given the Greens a clarity and continuity of meaning, message and purpose that the more centrist Democrats never had.

By contrast, the Democrats oscillated between messages as they oscillated between leaders, playing centrist one election and progressive the next, as a result eroding voter trust in the brand. In the end, the Australian Democrats could not even agree what colour their logo should be.

The Greens face no such problem of an ongoing identity crisis that tore their predecessor asunder.

A new party however, would face such a crisis from day one. Would the new party be 'liberal' or 'democratic', 'Left' or 'Right' or 'Centre'? What role would the members play and what powers would they have? How would its leaders be chosen? Where would the money come from?

There is simply no time or capacity to resolve such issues several months out from an election. This is something many potential leaders of such a party, from Malcolm Turnbull to Natasha Stott-Despoja, would factor into their thinking. It would take a remarkable event and a public groundswell such as that which accompanied the establishment of the Democrats in 1977, for a new party to attract the necessary talent and resources to challenge established parties, including the Greens.

Whatever the sizable dissatisfaction with the state of politics in Australia, there is no groundswell for a new political party today. Australians want their political parties to be better, not for there to be more of them.

The Greens have been the beneficiaries of both a protest vote, and a growing awareness among Australians of the environmental crisis our civilisation has reached. Australians who vote Green do so not merely because they may want a 'Green' government, but to send an effective message to the 'old parties' that they want change - and change in environmental policy in particular.

Green party philosophy has so far proven durable and flexible. While there are no doubt divisions in the party between 'light' and 'dark' greens, the Greens are part of a global movement towards ecology and sustainability that touches on all aspects of economic and democratic life as well as 'run of the mill' conservation issues. Far from driving voters away, the Greens consistency of message, as well as its deep relevance, is what makes it the third force in Australian politics today.

Political parties, like all organisations, have their time and reason - and the Greens are proving that this is their time.

Aron Paul is a former national president of the Australian Democrats.