Politics Professor Clem Macintyre, from the University of Adelaide, says negotiating with up to four independents would be challenging for any government.
“The whole situation becomes very unstable and you’d probably be expecting it to not last all that long,” he told ABC Radio on Friday.
“There’d be every chance that we’d be going back to the polls fairly soon.”
Most opinion polls point to a close result, prompting speculation of a hung parliament, with Labor falling short of the numbers it needs to rule in its own right.
Polling analyst Andrew Katsaras said if the polls were repeated on election day, Labor would not achieve an outright majority.
“It shows that a hung parliament is a real possibility,” he said, adding Labor would have either 73, 74 or 75 seats.
“The coalition would sit on about 72 or 73 and then we’d have three independents.”
That would hand the balance of power to three independents – Bob Katter (Queensland), and Tony Windsor and Rob Oakeshott (NSW).
There might also be an Australian Greens MP from the Labor-held seat of Melbourne,
Mr Windsor said he would consult with independent colleagues to determine if there was common ground between them.
“I’d also be interested in talking to the crossbenchers and minor parties in the Senate,” he said.
He said he would take into account which of the two major parties garnered the most lower house seats and won the popular vote.
Mr Oakeshott said he would be willing to talk to the major parties.
“My phone line is open,” he said.
“It is really their call, not my call, on how they want to approach that situation if it does arrive.”