Australian Greens Leader Christine Milne welcomes today's commitment from Shadow Treasurer Chris Bowen that a Labor government would enhance the role of the independent Parliamentary Budget Office.

"The Greens set up the PBO in our agreement with the former government and it has already improved accountability and transparency when it comes to promises made by all political parties," said Senator Milne.

"Just last month the Greens made an inquiry submission calling for greater powers for the PBO and greater transparency.

The Australian Greens say it's outrageous that other parties are shielding the federal parliament and public service from corruption investigations, by refusing to vote on the creation of a national version of ICAC.

"I am disgusted that Labor and the Abbott government have joined forces to stand in the way of a national ICAC and I think Australians will be too," said Greens Leader Christine Milne.

Ahead of the push for a vote on a national ICAC in the Senate tomorrow morning, the Australian Greens say both Labor and Tony Abbott's Liberals have failed to declare a position on the national anti-corruption legislation.

"We need to take urgent action on corruption and we can. It's never been more obvious that we need a national ICAC," Greens Leader Christine Milne said.

"What are Labor and the Coalition hiding from?

Parliament resumes next week and the Australian Greens will use their first opportunity on Thursday to push for a vote on the bill to bring a national anti-corruption body into law.

"We must restore public confidence that corruption is being stamped out. The national ICAC can be established quickly and easily. There can be no excuses from Tony Abbott and the Labor party," said Greens Leader Christine Milne.

"Revelations from ICAC and stories this week around shady political donations leave no room for the old parties to hide.

The Australian Greens have called on both Liberal and Labor to urgently consider legislation for a national ICAC-equivalent in light of recent events in NSW politics.

The Australian Greens have today announced that they will move quickly to drive electoral reform in the new parliament by referring the matter of optional preferential voting in the Senate to the Joint Standing Committee on Electoral Matters.

The Terms of Reference ask the Committee to specifically consider the matter of optional preferential voting in the Senate, which would see an end to preference deals and let voters decide where their vote goes.

The Greens have called on all parties to support legislative reform following more examples of inappropriate use of travel entitlements. Australian Greens Leader Senator Christine Milne said she would introduce a bill for a National Integrity Commissioner and Independent Parliamentary Adviser as soon as Parliament is recalled.

"The next wedding charged to the taxpayer should be an iron-clad marriage between elected public office and accountability with a National Integrity Commissioner," Senator Milne said.

Australian Greens Leader Senator Christine Milne said today that Western Australians stand to lose an intelligent and passionate environmental and social justice advocate in Scott Ludlam if the current Senate result stands.

The results show the count was knife-edge, with only 14 votes difference at a crucial choke point in the distribution of preferences. The Greens have lodged a request with the Australian Electoral Commission for a recount.

"The entire Party Room is devastated at the thought of Scott leaving the Senate next year," Senator Milne said.