Greens Senator Christine Milne says Labor has effectively ended its agreement with her party, by caving in to demands from the powerful mining sector,.
The Prime Minister, Julia Gillard has been under intense pressure, following the latest opinion polls, which show Labor would lose September's national elections.
The Prime Minister's strongest supporters have issued a rally cry at a major union event in Queensland's Gold Coast.
Correspondent: Girish Sawlani
Speakers: Christine Milne, Australian Greens leader; Simon Crean, Minister for Regional Australia; Wayne Swan, Australian Treasurer; Bill Shorten, Australian Employment and Workplace Relations Minister
SAWLANI: At the 2010 elections, the Australian Prime Minister Julia Gillard and the Labor Party, won government by just one seat. That was thanks to support from a small group of independent MPs and the Greens party which guaranteed supply of confidence to Labor in parliament.
Part of the government's agreement with the Greens was to legislate a major tax on the super profits made by the nation's biggest mining companies. But the relationship between the two parties has been strained by revelations that the tax raised just $126 million in its first six months, well short of the forecast 2 billion.
During an address to the Canberra Press Club, Greens Leader Senator Christine Milne delivered a scathing attack on the government.
MILNE: By choosing the big miners, the Labor government is no longer honouring our agreement to work together, to promote transparent and accountable government, the public interest or to address climate change. Labor has effectively ended its agreement with the Greens - well, so be it. But we will not allow Labor's failure to to uphold the spirit of our agreement, to advance the interests of (the Opposition leader) Tony Abbott. We will not walk away from the undertakings we gave, not only to the Prime Minister, but to the people of Australia - and that was, to deliver confidence and supply until the parliament rises for the election.
SAWLANI: Julia Gillard's been under increasing pressure, not least since the latest opnion polls showed the oposition leader Tony Abbott over taking Ms Gillard as preferred Prime Minister. The polls have also fuelled speculation that the former Prime Minister Kevin Rudd would have another tilt at the leadership. But on several occasions Mr Rudd himself has poured cold water on the rumours, telling reporters to put those ideas into cryogenic freeze.
Senior Labor Frontbencher Simon Crean described the poll as a wake up call for Labor. He says the solution to the party's woes is unity.
CREAN: I think that the Labor Party model in changing leadership everytime there's a bad poll is broken and discredited. It happened when I was the leader, it's happened since, what you can't have is a belief in the revolving door of leadership as the salvation to your position.
SAWLANI: Mr Crean's comments set the tone for a rally call by the Labor faithful and the chosen platform was the Australian Workers Union national conference at the Gold Coast. Wayne Swan is Australia's Treasurer.
SWAN: Turning up and standing up against the fear campaign that has been waged against us, particularly on carbon pricing. Staring down the bullying tactics of Tony Abbott. The prime minister has maintained her resolve and her determination, as we've gone about building our economic resilience and ensuring the gains we've made are fairly shared throughout our community.
SAWLANI: Prime Minister Gillard spoke at the conference a day earlier, calling for union support in the lead up September's general election. The call for unity has also been echoed by Australia Employment and Work[place Minister, Bill Shorten.
SHORTEN: I don't think there's a single MP in the Labor side who wants Tony Abbott to be the Prime Minister of Australia. I think that every Labor MP understands the value of unity and I know after my own conversations with plenty of people, that we're united in terms of supporting Julia Gillard as our leader.
SAWLANI: While there're almost 7 months to go before the elections, political pundits are not yet ruling out a shake-up in the Labor leadership, saying sparks could fly when parliament resumes next month.