The Greens have announced a new policy to make superannuation more equitable and raise $10 billion over the forward estimates. ‘A super system for everyone' will replace the current flat superannuation tax rate of 15% with a progressive system that is closely based on a person's marginal income tax rate.

"Superannuation in Australia has become a tax haven for the wealthy. It should be a way of delivering a comfortable retirement for everyone," Greens Leader Christine Milne said.

The Senate has this afternoon endorsed a Greens motion that calls on Treasurer Joe Hockey to raise revenue from the big end of town instead of imposing cuts on Australians who can least afford it.

"The Liberals have been running a protection racket for big business, at the expense of the community. That's why their government is failing," said Greens Leader Christine Milne.

"Whatever happens with their leadership in the coming weeks, I just hope the Liberals learn that they can't keep using government to protect tax avoiders at the big end of town.

Greens Leader Christine Milne says it's time for Treasurer Hockey to accept his budget has failed, instead of trying to trick the Australian people into accepting cruel cuts.

"The Treasurer keeps claiming there are no alternatives to his brutal attacks on the sick, the elderly, students and the unemployed. There are, but it will mean ending the age of entitlement at the big end of town," said Senator Milne.

"Just ditching tax breaks for big mining companies would boost the government accounts by $10 billion over the forward estimates.