And then there were three: again

The nation will have to wait until Monday at the earliest before knowing whether it will have a Labor or coalition government, as three key independents continue to ponder which party they will support.

Labor on Thursday edged closer to forming a minority government when Tasmanian independent Andrew Wilkie declared his support for Prime Minister Julia Gillard after more than a week of tense negotiations.

Mr Wilkie's backing of Labor minority government gives the party 74 members on its side, including Australian Greens MP Adam Bandt.

To form minority government, the ALP needs two of the three other independents who are yet to make up their minds.

After a day of meetings with both sides, including more than five hours with the shadow cabinet, Bob Katter, Rob Oakeshott and Tony Windsor say they want the weekend to think about which party they will back.

The trio on Friday will release a parliamentary reform document calling for all legislation to go directly to a committee that would discus amendments before being debated in parliament.

Their decision on who they will support could be announced as early as Monday, although comments from at least two of the hold-outs suggested it would more than likely be later in the week before the matter is resolved.

Perhaps crucially, Mr Oakeshott said the move by Mr Wilkie to side with Labor would be a factor in his decision to side with the party which offers the greatest stability.

"As this week unfolded the race to get to 74 (seats) was a pretty important one," Mr Oakeshott told Sky TV on Thursday night.

"It's not the deal maker or breaker but everything is in play and I think if we are being genuine about stability, both what Adman Bandt and Andrew Wilkie have done ... is obviously a factor in all of our decisions."

Mr Windsor hopes to make a call by Monday.

"I think we're getting to the pointy-end of the deal," Mr Windsor told Sky News.

"We've garnered a lot of information and now it is time to actually sit down and make a decision."

The three also defended themselves for not having made a decision earlier, with Mr Katter saying if a call had been made before the coalition's costings were released, it would have been wrong.

"If we'd made (a decision) on the basis of promises made by the coalition during the election campaign, we'd have made a bad error. We'd have looked very, very foolish indeed," Mr Katter said.

Earlier, Mr Wilkie, who negotiated separately to the other three independents, declared Labor had won him over with promises to tackle problem gambling and to boost hospitals.

Mr Wilkie won $100 million and possibly more to rebuild the Royal Hobart Hospital, along with a commitment to force the states to introduce a uniform smart card system on poker machines if they won't volunteer.

Opposition Leader Tony Abbott had agreed to gaming reform, but hadn't detailed his promise, Mr Wilkie said.

He said he was suspicious of Mr Abbott's offer of $1 billion for the Hobart hospital, after he failed to explain where the money would come from.

He said he had more confidence in Ms Gillard and urged the other independents to get on board.

"I hope that they follow me," he told reporters in Canberra.

"I want a Labor government. For all its weaknesses and faults, I think it would be the best government out of the two for the next three years."

Hours before Mr Wilkie's decision, the coalition had been on the back foot in critical talks with Mr Windsor, Mr Oakeshott and Mr Katter.

The three met shadow cabinet in Canberra after their inquiries with Treasury found between $7 billion and $11 billion in discrepancies in coalition costings.

The coalition downplayed Treasury's queries as mere differences of opinion, with Mr Abbott arguing the independents had more to consider than the costings quibble.

"There are a whole lot of issues in play here and at times an arcane argument about costings is by no means the most important," he told reporters in Canberra.

Ms Gillard seized the chance to question Mr Abbott's integrity.

"Now of course, we know he had 11 billion reasons why he wanted to keep these costings a secret," she said.