Senator Di Natale took up the leadership reins in May last year after the surprise resignation of then-leader Christine Milne.

The son of migrant parents is seen by many as having already begun steering his party towards a more moderate approach to politics.

The two previous Greens leaders, Bob Brown and Christine Milne, cut their political teeth as environmental activists in Tasmania.

But Senator Di Natale says the Greens stand for much more than just the environment.

He says the party appeals to a very broad range of voters.

"I think the future for us as a party is very bright. We are the natural home of progressive, mainstream, Australian voters. We are the natural home, and we are going to give voice to their concerns - decent healthcare, decent education, affordable housing, public transport. We are going to give voice to all of those issues and as leader they are things that for me mean a hell of a lot."

But just who is the man who would help shape the nation's way forward?

Doctor Di Natale grew up in Melbourne and worked as a general practitioner and public-health specialist before entering politics.

He's worked in Aboriginal health in the Northern Territory, on HIV prevention in India and in the drug-and-alcohol sector.

He says his experience has taught him what governments need to do for people's wellbeing.

"It became pretty clear to me that if you want to improve people's health, you've got to start looking at the things that make people sick. You've got to have a clean environment. You've got to have clean air and clean water. You've got to make sure that people have a roof over their head, that they've got a decent education, that they've got meaningful work and they've got a social safety net if they get into trouble. They are the ingredients of good health care, and I'm going to be champion for that."

The Greens leader says it is a matter of choosing to make good health care a priority, not a question of whether Australia can afford it.

Dr Di Natale says he's not ignoring climate change because if that is not addressed successfully, every other issue becomes redundant.

He says human-induced climate change poses the greatest threat to our world and civilisation and urgent and sustained local, national and global action is required to mitigate its effects.

The father of two, who lives with wife Lucy in Victoria's Otways Ranges, played Australian Rules football in the VFA for six years and labels himself a long-suffering Richmond Tigers fan.

Dr Di Natale has made it clear, too, he has not forgotten his Italian roots and says he's a great supporter of multiculturalism.

"I'm a product of the great Australian experiment called multiculturalism. I want to be a champion of multiculturalism in the parliament. It's taking a beating at the moment. I think the debate on terrorism and refugees means that ... um ... that the multiculturalism issue needs a champion. And I'm going to be that champion."

At the moment the party has 10 seats in the Senate and is hoping to pick up more, especially because of the changes to how people are elected to the upper house.

Also, double-dissolution elections generally make it easier for minor parties because it halves the quota of votes senators need to get elected.

However, opinion polls are indicating that the election could go either way, with Labor and the Coalition garnering almost equal voter support.

If accurate, a clear decision on who will lead the country after the election may be impossible.

Both Labor and the Coalition have ruled out a powersharing deal with the Greens if the July election should result in a hung parliament.

But Senator Di Natale remains confident of the role the Greens would play in that eventuality.

"It makes much more sense to enter into a responsible power sharing arrangement and I think that's what you'll see. You'll see both sides of politics after the election talk to the Greens and independents and hopefully what we end up with then is an outcome where we get multi-party government, which I've said on a number of occasions will be the future for Australia."

Richard Di Natale says while it'll be a party decision, he personally wouldn't want to form a minority government with the Coalition.

He says it's inconceivable the Coalition would be supported to have another term.

"The Greens have already said that we would negotiate responsibly in the event of a hung parliament. But we have also said that given this government's record on global warming and preventing the action that is necessary there, on the cruel and harsh treatment towards innocent people seeking refuge and asylum, on so many issues. On the arts for example, cutting funding to the arts sector. This has been a terrible government for the country."

But it's the Senate where the Greens would wield real power if successful.

The race for Senate seats appears to be still wide open with new analysis showing 12 seats will hold the key to the balance of power.

Analysts are predicting the Coalition to win at least 30 out of the 76 Senate seats, while Labor should pick up 25, the Greens nine or ten and the Nick Xenophon Team three.