Prime Minister Kevin Rudd will swear his cabinet in next Monday, but has warned he will not immediately be launching an "avalanche of policy decisions".
Mr Rudd, who ousted Julia Gillard on Wednesday, will also reward MPs who supported his return to the leadership after three years.
So far, Treasurer Chris Bowen has been sworn in to replace Wayne Swan, Anthony Albanese has been named deputy prime minister and Gillard ministers Stephen Smith, Gary Gray, Don Farrell and Penny Wong are staying.
Senator Kim Carr is being tipped for a mega-portfolio taking in industry, climate change and research, and the other winners may include Jason Clare, Senator Jacinta Collins, Richard Marles, Joel Fitzgibbon, Ed Husic, Yvette D'Ath and Shayne Neumann.
A cabinet meeting on Monday will consider key policies to take into the election, which is now likely to be held in August - two or three weeks earlier than the previously proposed September 14 date.
Mr Rudd's Labor could alter the Gillard government's policy on the carbon tax, which is due to rise on Monday by $1.15/tonne to $24.15, to allow a shift to an emissions trading scheme in 2014 instead of 2015.
While this could offset the coalition's anti-carbon tax campaign and ease pressure on business, the prospect has angered the Australian Greens.
"Undermining the (clean energy) package for political reasons only ... doesn't accelerate efforts on climate change," Greens leader Christine Milne said.
The first opinion poll taken after Mr Rudd's return shows the opposition remains on track to win this year's election.
The 7News Reachtel poll of 3000 respondents, taken on Thursday night, has the coalition ahead 52-48 per cent, after preferences.
If that result was repeated at an election, leader Tony Abbott would be able form government with a majority of about 20 seats.
But Labor has narrowed the coalition's lead by six percentage point while Mr Rudd is preferred prime minister, leading Mr Abbott 52-48 per cent.
"The Liberal party has been very cocky for three years - they weren't cocky yesterday," home affairs minister Jason Clare told the Nine Network on Friday.
"They know now that the fight is on and there's a real competition at the next election."
Deputy opposition leader Julie Bishop called on Mr Rudd to end speculation about the election date.
"The Australian people deserve better. They deserve stable, competent government, and they deserve to know when the election will be," she said.
