Federal parliamentarians return to Canberra for the final sitting weeks before the budget with battles looming for the government over its climate and referendum proposals.
During the next sitting fortnight, the government hopes to pass its bill to change existing referendum laws, laying out groundwork for the upcoming vote on the Indigenous voice to parliament.
Ahead of the main referendum bill being introduced, the government is seeking to finalise separate laws detailing rules about the distribution of referendum information and political donations.
But while it passed the lower house during the last sitting week, a myriad of crossbench amendments could stall the machinery bill in the Senate.
Trade Minister Don Farrell, who has been negotiating with the coalition, Greens and Senate crossbench on the matter, said he was confident the bill would pass.
Senator Farrell said the government's bill was a sensible change intended to modernise how referendums were held.
"This is not a debate about whether you support yes or no in the referendum," he told Sky News on Sunday.
"This is about ensuring the experience that the people get when they go to the referendum is as close to the experience they get at a general election."
The government is also seeking to get its signature climate change proposal to establish a safeguards mechanism through parliament.
To do so, it will need the votes of the Greens and two others in the Senate.
But Greens leader Adam Bandt wants the government to end coal and gas development as part of the bill, which Climate Change Minister Chris Bowen has ruled out.
The Senate will also consider a workplace equality bil,l requiring companies with more than 100 staff members to publish information about their gender pay gap, and bills to establish the National Reconstruction Fund and Housing Future Fund.
Meanwhile, Treasurer Jim Chalmers has labelled the opposition dishonest and deceptive about his proposed superannuation reform.
The planned changes would double the tax rate on super accounts with more than $3 million to 30 per cent, with the changes to come into effect from mid-2025.
Treasury projections showed a 2017 change to superannuation by the coalition that was not indexed would affect three times as many retirees in 30 years compared to the government's proposal.
The new projections showed at least the top 30 per cent of earners retiring in 2052 would have paid additional contributions tax in their working life under the threshold legislated by the coalition.
Dr Chalmers said the figures revealed the opposition's "dishonesty, deception and double standards".
"All their hypocrisy and hyperventilating is to distract from the fact that they want to add to the trillion dollars of Liberal Party debt to fund bigger tax breaks for people who already have tens of millions in super," he said.
He said the government's policy was a modest and sensible change.