Australian Greens leader Christine Milne is a survivor.
In February 2011, six federal MPs stood in the Prime Minister's Courtyard in Parliament House to announce the details of Labor's forthcoming carbon tax.
Julia Gillard, Greg Combet, Rob Oakeshott, Tony Windsor and Bob Brown have exited federal politics, but Milne remains.
Milne, a former high school teacher, was elected to the Senate for Tasmania in 2004.
She took over the Greens leadership from Brown - who had been the public face of the party since its formation - in April 2012.
As leader, Milne has been a key figure in delivering Labor's Clean Energy Future legislation, putting the spotlight on coal seam gas development, banning the super trawler and standing up for the rights of asylum seekers.
She also ended the Greens agreement with Labor - signed after the 2010 election to deliver a minority government - citing the poor design and low revenue earnings from the government's mining tax.
Gillard's reaction to Milne's decision was a curt: "Thanks, righto ..."
But such a dismissal denies the importance of the Greens to Labor's prospects for re-election.
Labor will rely heavily on the minor party (which scored 11.8 per cent of the vote in 2010) for preferences in the race for Senate spots and inner-metropolitan lower house seats where the environmental vote is highest.
The Greens will also continue to hold the balance of power in the Senate until June 30, 2014, making a strong working relationship between the leaders of the key parties crucial to the passage of legislation.
Milne has vowed to recontest the Greens leadership after the election, which is spilled automatically after a poll.
She says the Greens party has "big things to deliver" in the coming term, including making the big banks and miners pay more tax, support for renewable energy and a better deal for the unemployed and refugees.
Marriage equality is a personal issue for Milne who has a gay son, Tom.
Unlike Prime Minister Kevin Rudd and Opposition Leader Tony Abbott, Milne doesn't face re-election in 2013 because her Senate term has another three years to run.
And the 60-year-old Milne, a veteran of the Franklin River campaign in 1983, is not one to shirk a fight.
