With 2016 federal election pre-polling now open, important differences have emerged between the major parties and all parties need greater scrutiny, a Charles Sturt University (CSU) academic says.

Associate professor in political science in the CSU School of Humanities and Social Sciences Dominic O'Sullivan (pictured) said the closeness of the major parties in the polls and the possibility of smaller parties playing significant roles in the next Parliament means that the Nationals, Greens and Xenophon parties ought to be subjected to much greater analysis.

"The Nationals will provide the deputy Prime Minister and senior ministers in a Coalition government, yet the election campaign's presidential style leaves the voter with little real information on the points that distinguish the two Coalition parties," Professor O'Sullivan said.

"This is bad for democracy.

"The ALP says it doesn't want to govern with the Greens. Yet, in the previous Parliament voters provided little choice; either an agreement with the Greens or risk another election.

"In 2016, it could be the Xenophon party whose support is required for either the ALP or Coalition to form government. The question is not just which larger group might be supported, but what will the smaller party demand in return for its support?"

Professor O'Sullivan noted that for both the ALP and the Coalition there is no longer a Budget 'crisis'; both are prepared to run deficits in the next Parliament.

"The Coalition is prepared to run short-term deficits to fund corporate tax cuts, while Labor will run deficits to fund the Gonski school reforms and to restore funding previously cut to public hospitals; the difference couldn't be more stark," Professor O'Sullivan said.

"The NBN, workplace relations and Medicare also provide voters with serious choices between Labor and the Coalition.

"The arguments are being put with equal conviction, but couldn't be more different in their long-term impact."