Voters at Saturday's election will be confronted with a dizzying array of minor parties whose disparate positions across the political spectrum loom as a significant challenge for the next government depending on results in the Senate.

An analysis of political parties' responses to the smartvote Australia tool - developed by the Australian National University in partnership with The Sydney Morning Herald and The Age - shows voters also have a "clear choice" between the two major parties, Labor and Liberal.

This election represents the first true test of the new Senate voting system, introduced by Malcolm Turnbull but impeded in 2016 because of that year's double dissolution election.

Preference flows between minor parties in the Senate may throw up surprising results, although ABC election analyst Antony Green argues there will be a "winnowing" of the crossbench to the benefit of the major parties.