Greens MP and banking spokesperson, Adam Bandt, has warned the big four banks to pass on the full interest rate cut or risk government support in the event they're hit by another financial crisis.

"Last time there was a financial crisis, the banks received significant support from the government and the Parliament. We gave them cheap credit and effectively guaranteed their operations", Mr Bandt said.

Greens MP Adam Bandt has repeated his demand for a inquiry into the RBA banknote scandal following revelations of Austrade involvement in today's Age newspaper.

Mr Bandt says the government can no longer ignore the growing smell around the bribery affair.

"The scandal has now spread to Austrade", Mr Bandt said.

"There is a real smell around this affair and the government must clear the air."

"The government must find out who else in Austrade and the department knew what was going on to secure these banknote contracts."

Greens MP and spokesperson for innovation, industry, science and research Adam Bandt has criticised the government's announcement of a near doubling in HECS fees for maths and science students in today's mid-year mini budget.

"Almost doubling university HECS fees for maths and science students is economic stupidity. How can science and maths be a national priority two years ago and now not be?," Mr Bandt said.

Australian Greens Leader Bob Brown and the Member for Melbourne Adam Bandt talk to reporters in Canberra about the mining tax, after the Prime Minister's MRRT announcement.

Senator Brown said superannuation taxation arrangements can be made much more socially equitable and the Gillard Government's open cheque book approach to refunding mining companies for royalties paid to states should be reviewed by the Senate.

Australian Greens Leader Bob Brown and Member for Melbourne Adam Bandt outlined the Greens' position on the MRRT, namely to protect the revenue stream from moves in Parliament to further water down the mining tax.

The Greens will also move for a debate on setting a date for a safe exit of Australian troops from Afghanistan.

Greens MP and industry spokesperson Adam Bandt has welcomed the passage of the Steel Transformation Plan Bill, but is disappointed Labor failed to back a Senate amendment to support the creation of clean energy jobs in the Illawarra and other regions.

The amendment would have required allocations of the $180 million for Bluescope steel to take into account the joint union-business Green Jobs Illawarra Action Plan.

"This package will help protect jobs and assist in a transition to a cleaner economy," Mr Bandt said.

Australian Greens Leader Bob Brown, Senator for Queensland Larissa Waters, Senators for Western Australia Rachel Siewert and Scott Ludlam, and Member for Melbourne Adam Bandt spoke to the media about the Australian Greens National Conference in Fremantle, WA.

Topics included the allocation of preferences, the environmental threats posed by developments in the Kimberley, and the Nationals' call for a "discussion paper" on coal seam gas. 

Greens MP and employment and workplace relations spokesperson Adam Bandt will introduce a private members bill next sitting week to prevent future escalation of industrial disputes along the lines of the recent Qantas lockout.

The bill will close the loopholes in the Fair Work Act that allowed Qantas to hold a gun to the government's head by escalating to a lockout without any real notice.

Greens MP Adam Bandt says the Government's excuse for excluding gold from the mining tax does not wash.

Mr Bandt asked the Treasurer about putting gold in the mining tax in Question Time today.

"Gold is traded on international and local markets. To suggest it can't be taxed because it is mined with other minerals is simply not right", Mr Bandt said.

"Mr Swan's explanation does not wash. His own department recommended gold be in the original mining tax."