Prime Minister Julia Gillard has agreed to a swag of demands from the Greens as part of a formal deal to join forces as Labor tries to secure a parliamentary majority.

The agreement includes the dumping of the highly unpopular 'Citizens Assembly' which Ms Gillard announced as one of the planks of her election campaign climate change policy.

However, the Greens did not get Labor to commit to a price on carbon or any move towards legalising gay marriage, with Greens leader Bob Brown saying the deal is still a "work in progress".

Labor has also stuck to its original stance that it would not offer the Greens a ministry.

Ms Gillard and Senator Brown have signed the deal, which ensures newly elected Lower House Greens MP Adam Bandt will support the formation of a minority Labor government.

The concessions secured by the Greens include:

the formation of a climate change committee

the formation of a climate change committee a parliamentary debate on Afghanistan

a parliamentary debate on Afghanistan a referendum on recognising Indigenous Australians

a referendum on recognising Indigenous Australians restrictions on political donations

restrictions on political donations legislation on truth in political advertising

legislation on truth in political advertising the establishment of a Parliamentary Budget Committee

the establishment of a Parliamentary Budget Committee a parliamentary integrity commissioner

a parliamentary integrity commissioner improved processes for release of documents in Parliament

improved processes for release of documents in Parliament a leaders debates Commission

a leaders debates Commission a move towards full three-year parliamentary terms

a move towards full three-year parliamentary terms two-and-a-half hours of allocated debate for private members' bills

two-and-a-half hours of allocated debate for private members' bills access for Greens to various Treasury documents

If Ms Gillard stays on as prime minister she would also meet with Senator Brown and Mr Bandt once a week during sitting weeks.

Senator Brown says the Greens, who also hold the balance of power in the Senate, are committed to stable, open and good governance.

"We take that responsibility with a great deal of gratitude to the people of Australia," he said.

"We will be discussing, if Julia Gillard is the next Prime Minister, a wide range of other issues in the months and years to come.

"Here is a very good example of us saying, 'we accept what the people of Australia say and we're moving to get them a good outcome from [a minority government]'."

But Opposition Leader Tony Abbott has accused Ms Gillard of breaking an election promise by dumping the Citizens Assembly.

"It was always a dud policy, but it was hers, and now it's been junked at the direction of the Greens," he said.

"[For Labor] there is no election committment that is so important and so certain that it won't be junked in the quest to hold onto power."

Senator Brown defended the formation of climate change committee in the absence of a price on carbon and said all sides of politics as well as various experts would be invited to join it.

The deal with the Greens means Labor is now three seats short of the 76-seat majority it needs to form government.

The Coalition is also on 73 seats if Western Australian Nationals MP Tony Crook is included.

The three incumbent crossbench MPs and newly elected independent MP Andrew Wilkie are yet to make up their minds on who to support as negotiations continue this week.

Senator Brown says he informed Opposition Leader Tony Abbott of the deal last night.

"He told me that he would attack any agreement we signed up on. I said, that's his right, we have made a decision here," he said.

If Mr Abbott forms government Senator Brown says he will meet with him to discuss how things would operate in the Senate.