The three country independents whose support is needed to form a new federal government say talks during Tuesday morning will be crucial to which of the two major parties they back.
Their decision is expected to be announced mid-afternoon, and they have promised the voting public - rather than Prime Minister Julia Gillard or Opposition Tony Abbott - will be the first to know.
However senior coalition figures are pessimistic about the outcome.
Talks are under way in earnest in Parliament House between the independents and Mr Abbott and Ms Gillard, based on what have been described as "final documents".
It is understood Labor and the coalition received a fresh list of demands from the independents on Monday night, including better support for regional areas.
Mr Windsor told reporters once meetings with the leader were over, the trio would meet and "talk it through".
Mr Windsor admitted he was leaning one way but would not say whether it was towards Labor or the coalition.
He hasn't even told his wife.
"She wanted to know. No. She can't be trusted," he told reporters.
Nor have the three MPs yet talked to each other about their "specific votes".
Labor needs only the support of two of the three independents to form a minority government, while the coalition needs all three.
Nationals Senate leader Barnaby Joyce is not confident about the coalition's chances of winning over the independents.
"You get a sense that the momentum is slipping away from us," he told ABC Radio.
But his opposition frontbench colleague Andrew Robb is still hopeful the independents will back the coalition, describing private negotiations as genial and constructive.
"They have given us the impression they are still weighing up issues on both sides," he said.
Mr Robb rejected criticism Mr Abbott had lost the negotiation battle, despite running the better election campaign.
Mr Windsor says stability of government remains the most important issue for him.
"What we all want to avoid, and I think the community as well wants to avoid, is a 75-all draw which would mean another election," he said.
Independent Rob Oakeshott told reporters Mr Abbott and Ms Gillard would both make a good prime minister.
The MP said he hoped there would be some respect for the hard decision the independents had to make.
"Hopefully there is a recognition this is an unnatural choice that the three of us have got to make."
