Greens leader Christine Milne has used her speech to the National Press Club to announce the end of her party's alliance with Labor.
Citing a growing rift in environmental policies on coal seam gas and coal mining, Ms Milne said Labor had effectively ended the alliance signed following the 2010 election.
"So be it", she said.
By 'choosing the big miners', Labor was choosing to walk away from the alliance, Ms Milne said.
Ms Milne said she is still determined that parliament would run its full term, and that an election will be held on September 14.
More to come