Independent MP Bob Katter says it looks like Tony Abbott has something to hide, after the Opposition Leader refused to submit his costings to Treasury for analysis.

Mr Katter and fellow independents Rob Oakeshott and Tony Windsor say they want Treasury to be allowed to cost both party's election promises, as part of a seven-point list of demands to both Prime Minister Julia Gillard and Mr Abbott.

However Mr Abbott says Treasury should not be providing that advice on the Coalition's plans, and says the Opposition instead wants to hand in its own costings analysis.

Kennedy MP Mr Katter told ABC TV's Lateline that Mr Abbott's refusal makes it look as though he has something to hide.

"The reaction of everybody in Australia would be, what's Tony got to hide here?" he said.

"I most certainly think that it is our duty as responsible Members of Parliament to have costings done on both sides, the promises of both sides of the Parliament.

"It would be very irresponsible of us not to go to the public service of Australia, to assess what is being put forward by Tony Abbott.

"I just can't understand Tony Abbott's intransigence on this issue and of course he's the one that looks so bad."

Mr Katter says Mr Abbott's refusal on the issue is a bad move if he wants the support of the Independents.

"Now if he looks so bad, and he's got something to hide, it makes it much more difficult for us to give him the gong to become prime minister," he said.

Mr Katter says this is a terrible blunder on the part of the Coalition.

"If you think the Australian people are going to put up with this sort of tomfoolery, you've got another thing coming," he said.

The independents say Treasury should be given a chance to show it can analyse the Coalition's policies.

Mr Windsor says Mr Abbott's position is not acceptable.

"I think it's appropriate that both sides be costed by the same person," he said.

Not the end

Mr Windsor says it is not the end of the negotiations with the Coalition, but he stresses Mr Abbott should change his mind.

But Mr Abbott says he will be providing the Coalition's own costings instead.

He says Treasury cannot provide adequate advice about the Opposition's policies.

"It is very difficult for the public service to understand the Coalition policy, Opposition policy with the same degree of insight and depth that it has of Government policy, I mean that's just the nature of these things," he said.

He says instead the Opposition will provide its own costings and allow extensive access to shadow ministers.

"I want to be as candid and as upfront with the non-aligned independents as I can be," he said.

Prime Minister Julia Gillard says she is keen to assist on the issue.

The independents spent over an hour with each leader on Wednesday afternoon in an attempt to decide which party they will help form a minority government.

The independents want briefings from the heads of 10 government departments, including Treasury, Education, Broadband, Health and Defence.

Both Ms Gillard and Mr Abbott say they will meet the independents' request to serve a full parliamentary term.