Greens leader Senator Christine Milne has announced the end of the formal alliance between Labor and the Greens, but pledged to continue to vote against no confidence motions and for supply bills in order for the parliament to continue until the September 14 election day.
Directly challenging Labor's election pitch that it stands for ''fairness'', Senator Milne accused the Gillard government of ''walking away from its agreement with the Greens and into the arms of the big miners''.
''Labor's priorities lie with powerful mining interests not with the people and the Greens,'' she told the National Press Club, saying it was Labor - by its actions - who had effectively ended the alliance with her party.
Senator Milne said the Greens were proud of the clean energy package implementing the carbon price, the start of a national Denticare scheme and the introduction of a Parliamentary Budget Office, and attacked Labor for allowing mining in the Tasmanian Tarkine wilderness, for reducing payments to single mothers and for subsidising ''big miners'' and fossil fuel exports.
She promised to ''deliver confidence and supply until the Parliament rises for the election''.
''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,'' she said.
''We will not walk away from the undertaking 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.
''We will see this parliament through to its full term.''
She said ''the Greens will not add to the instability that Labor creates every day for itself''.
Responding to the speech, a spokeswoman for Prime Minister Julia Gillard said: ''This is a matter for Christine Milne and the Greens. We will always be the party that puts jobs and growth first.''
Ms Gillard and her deputy Wayne Swan signed the agreement with the Greens on September 1, 2010, after the election on August 21 did not result in either major party achieving a parliamentary majority. Along with her agreements with three independents, the agreement allowed Labor to form government.
Deputy Prime Minister Wayne Swan said Senator Milne's decision would not have any practical impact on the operation of the Parliament, as the Greens would continue to support the government on supply and confidence motions.
“The Greens have opposed quite a few bills during the last few years but the Parliament has functioned very well,” he said ahead of a speech to the Australian Workers' Union conference on the Gold Coast.
Mr Swan said the Labor Party always put jobs and growth first and would “get on with the job”.
“The Labor Party and the Greens are cut from a different cloth,” he said.
“We don't pander to special interests on our left or the right.”
Mr Swan argued the Greens wanted to abolish the mining industry, a view he described as “fringe”, while the Liberal Party did not want miners to pay their fare share.
The Treasurer said he did not have anything to fear from a potential Senate inquiry into his handling of the mining tax, which has collected much less revenue than originally forecast.
Senator Milne insisted Labor would not have introduced a carbon price if it had been elected in its own right.
''We have a carbon price in Australia because of the Greens. If it had been Labor on its own or the Liberals on its own we would not have a carbon price,'' she said.
Industry Minister Greg Combet said Senator Milne was engaged in political ''product differentiation''.
And Australian Workers' Union national secretary Paul Howes accused Senator Milne of trying to score ''cheap headlines'' in retaliation over the federal government's decision to reject World Heritage Listing for the Tarkine wilderness.
''This is just a political ploy by Christine Milne because she's upset that she lost the campaign in north-west Tasmania. Well, boo hoo. At the end of the day the federal Labor government has done the right thing for jobs,'' he said.
''Frankly for Christine Milne to say that Julia Gillard hasn't delivered for the environment after she introduced a carbon price demonstrates how out of touch with reality Christine Milne is.''
Mr Howes also questioned the practical impact of the Greens' decision, saying the minor party had been opposing a range of Labor initiatives for some time and would still support the government on supply and confidence votes.
He said Senator Milne was ''a leader who's struggling'' with a collapse in support after predecessor Bob Brown's retirement.
''Frankly if Christine Milne wants to rip up an agreement, excellent,'' Mr Howes said.
''I'm not surprised. These are people that can not handle doing things pragmatically, these are people that cannot handing doing things sensibly."
Mr Howes said Labor and the Greens did not share common objectives. Labor stood for protecting the environment but this must be done ''pragmatically and smartly'' and would not ''sacrifice jobs at the altar of Green ideology''.
with Daniel Hurst