While Labor and the Coalition have been brushing up their opening pitches of health and education versus jobs and growth, the Greens have been grabbing headlines: talking up their potential power in a hung parliament; getting front page treatment in Sydney's usually anti-Labor Daily Telegraph, which urged its readers to "Save Our Albo" over a Greens threat to Anthony Albanese in the inner city seat of Grayndler; trying to outdo Labor on protecting penalty rates, and reaping yet more publicity as Peter Dutton pounced on Greens asylum seeker policy to warn voters that illiterate refugees were going to swamp Medicare queues and swipe Aussie jobs. "I take a long view about our chances in the lower house": Greens leader Richard Di Natale. Credit:Alex Ellinghausen The Coalition has been talking up the Greens ogre with gusto, every Liberal frontbencher working off a script yoking Labor and the Greens in a putative alliance as if it was a done deal, despite the fervent protestations of Labor leader Bill Shorten to the contrary. Mathias Cormann, the government's campaign spokesman, told Fairfax Media that "we see them very much on a unity ticket. In our judgment, Labor and the Greens are now on an anti-business, anti-jobs, and anti-growth unity ticket" with Bill Shorten "dragging his party to the left" as a consequence. These claims madden Labor's strategists, who also deeply resent the way the Greens waded into penalty rates this week.

Campaigning in inner Sydney and Melbourne, Di Natale and his industrial relations spokesman Adam Bandt (so far the only lower house Greens MP in the federal parliament) promised to introduce legislation to shore up penalty rates, with Di Natale styling himself the defender of "ordinary working people" and their "hard-earned, old-fashioned rights". Richard Di Natale and his wife, Lucy Quarterman, on their Deans Marsh property. Credit:Damien Pleming Having already made inroads on Labor's socially progressive left flank, the Greens looked as if they were going after the ALP's wage-earning heartland as well. Labor's campaign spokeswoman Penny Wong was quick to retort that "we are the party that has decades of history supporting and protecting the rights of working people". And Shorten struck back with the argument that if penalty rates were ruled on by parliament instead of the workplace umpire, that would make them vulnerable to rollbacks by Coalition governments. Greens candidate Jim Casey and rival Labor MP Anthony Albanese. Credit:Dominic Lorrimer

More wounding to Di Natale was a Fairfax Media story several days later alleging he had failed to declare his farm correctly on the parliamentary interests register and that he and wife Lucy had underpaid a series of au pairs. Employment Minister Michaelia​ Cash leapt on the story to accuse the Greens of reaching "record levels" of hypocrisy. Di Natale has denied the thrust of the story, saying the working farm was declared as a business interest, and that the au pair's salary package (which included food and board) was negotiated according to advice from the agency they used when Lucy was still working two days a week (she has since taken a break from work). I welcome attacks because they make us stronger and more determined. Greens leader Richard Di Natale. "I think I said in my first ever speech, I welcome attacks like this because they make us stronger and more determined," he said defiantly on Friday. "What the old parties haven't understood is that the biggest barrier to the Greens vote going up is that most people don't have a deep understanding about the Greens: who we are and what our positions are on a number of key issues. When you are able to have that conversation with people either through the media, or face to face, you find as often as not that you end up with someone who is a new Greens voter."

Maintaining a profile is always the critical challenge for a small party and Greens elder statesman and former leader Bob Brown also insists that assaults on the Greens may not always play out the way the major parties intend. "Richard is proving a huge asset as leader of the Greens, and he and Adam Bandt can hold their own as quality spokespeople against any of the major figures in the Labor and Liberal parties," he told Fairfax Media this week. Brown will be making a temporary return to the campaign trail this election, his first formal appearance slated for June 4 in the seat of Higgins (held by Liberal frontbencher Kelly O'Dwyer) in support of the Greens' candidate Jason Ball. Kevin Rudd's former media chief Lachlan Harris, a veteran of several federal election campaigns, says Labor is deeply concerned that the Greens are becoming a "a more formidable political force" and he assesses the Greens' campaign operation as "smarter and more capable of taking tactical opportunities than they used to be". But he says if the Greens are getting more than their expected share of the spotlight, its also because the major parties' campaigns thus far have failed to catch fire. "The fact that the tactical plays of the minor parties are getting quite a bit of coverage tell me that the Greens are probably filling a bit of a vacuum. I have never seen a campaign, for the last 20 years, where there has been a lower level of interest in the community in the first few weeks," he says.

Harris also insists that Labor is deadly serious about preferring a fresh election to getting back into bed with the Greens – as it did during the Gillard years – in the event of a hung parliament. "If Labor positions itself in a coalition agreement then the Libs will outflank it to the right, the Greens to the left and it gets stranded in the middle with nothing. I would say there would be no circumstances where it would not be a better option to return to the polls." Despite this, the Coalition appears ready to run this line of attack right up to polling day. The tactic invites comparisons with Britain's 2015 general election and the way Prime Minister David Cameron constantly talked up the risk of a British Labour pact with the Scottish National Party in order to panic voters back into the conservative fold. But keeping the focus on the Greens may not be all upsides for the Liberal party either. Election analyst Antony Green says that in last year's NSW state election, the Greens polled surprisingly strongly in some of Sydney's wealthier suburbs, coming second after the coalition. Carried over into the federal sphere, this could translate into some leakage of Senate votes from both the Coalition and Labor. "All this oxygen that the Greens are getting could deliver them an increased Senate vote, and I don't think the Liberals think enough about that, they are just focused on winning the Treasury benches" insists one Greens strategist. "Don't forget that at the state election in NSW the Greens won a seat off the Nationals in Ballina, and off the Liberals in Prahran in the Victorian state election."

The Greens also hold two inner city seats after the 2015 NSW state election – Balmain and Newtown – both of which are now within the redrawn boundaries of Albanese's inner-city electorate in Sydney. Di Natale singled out Albanese's seat of Grayndler as a target on day one of the campaign, infuriating Labor's former deputy prime minister, who accuses the Greens of hypocrisy in seeking to oust him while stating they want a more progressive Australia. Labor stalwarts find it particularly hard to stomach what they see as the Greens "holier than thou" attitude on issues like asylum-seekers, which is a running sore for the ALP. "There is nothing quite so righteous as a politician that never has to govern," says Harris. Critics point out that the Greens can champion an asylum seeker policy advocating 50,000 entrants a year and freer-flowing regional processing – while asserting that this would not re-start the boats – because neither major party is going to adopt it and put it to the test. The Greens' ever-broadening policy agenda poses other pitfalls. Di Natale looked exposed on the fine detail of foreign policy this week when he addressed the Lowy Institute in Sydney. Having advocated that China's belligerence in the South China sea should be dealt with by way of an international tribunal ruling, he had no comeback to the questioner who pointed out that China had forcefully rejected such arbitration.