Federal independent MP Rob Oakeshott has rejected an offer to become regional affairs minister, saying it would compromise the package he negotiated with Julia Gillard.

As part of the deal with Ms Gillard that helped her form a minority government, Mr Oakeshott was offered the portfolio, but this afternoon he told the Prime Minister he would not join her frontbench.

Mr Oakeshott says there is still a lot of political heat around his position and there would have been problems for the regional package he negotiated if he was also the relevant minister.

"It was quite a genuine consideration over the last two days and it was a consideration in its own right," he said.

He says the package can be better delivered by someone with potentially less thorns on them than he has at the moment.

"The main consideration was the regional Australia package and making sure it survives the next three years of parliamentary life, and it not being killed along the way by political games that might get played," he told said.

"I think there are some organisations still in Parliament that may want to bring the package down via me, and if I am genuine that this package is important then I'm hoping - and it is a judgment call again - I'm hoping that it can be brought home by someone with potentially less thorns on them at the moment than me."

Mr Oakeshott says the amount of time he could spend with his young family was also a factor in his decision.

Independent senator Nick Xenophon thinks Mr Oakeshott made the right decision to stay out of the ministry.

"I just think it poses all sorts of difficulties for him. It just puts him in a very awkward position," he said.

"I think it would be a poisoned chalice for him. I think he needs to win over that part of the electorate that isn't happy with his decision to side with Labor.

"I think it'll be more difficult to win over those dissenting parts of the electorate."

But Tasmanian Greens leader and a minister in the state's Labor minority government, Nick McKim, thinks Mr Oakeshott has missed a golden opportunity.

"I don't see it as a poisoned chalice, in fact to the contrary," he said.

"Certainly in the Tasmanian context it's been beneficial. We've done so under a model that allows us to maintain policy integrity.

"We've found that we are better placed from accepting Cabinet decisions to push Green issues within the mechanism of government."

Mr Oakeshott's decision paves the way for Ms Gillard to finalise the rest of her frontbench and she is likely to announce the line-up tomorrow.

Former prime minister Kevin Rudd is expected to take on foreign affairs, meaning West Australian MP Stephen Smith will need to be shifted, possibly to defence where John Faulkner has left a vacancy.

Chris Bowen could be headed to finance, replacing Lindsay Tanner who has left the Parliament.

Greg Combet could be shifted to climate change, meaning Penny Wong will also need to be moved, possibly to the Attorney-General's position.

The ABC understands a number of senior ministers have already been told what their roles will be, while jostling for outer ministry spots is continuing.

Ms Gillard's new ministry will be sworn in by the Governor-General on Monday.

Opposition Leader Tony Abbott will wait until the Government has announced its line-up before revealing minor changes to his frontbench.