Parliaments exist to share power, and power sharing has been a feature of Australian parliaments for as long as they have existed: between different interest groups, different communities and different political movements; across the upper and lower houses; within parties (via factions); and between parties (including coalition agreements like those between the Liberals and the Nationals).

Despite occasional fearmongering about 'hung' parliaments, minority government and 'coalitions of chaos', the reality is that power sharing governments are common in Australia. Governments often need to secure the support of other parliamentarians, whether through the formal, albeit secret, coalition agreements between the Liberal and National parties or various arrangements with independents and minor party MPs.

The likelihood of shared power in the Commonwealth parliament has increased as the major party vote has declined significantly since the end of World War 2, and the 2022 election marked the lowest combined vote for the two largest parties since the Great Depression. It also yielded the largest House of Representatives crossbench ever.

This discussion paper examines the history of power sharing in parliaments around Australia. The authors also argue that declining voter support for the major parties, combined with the fact that independents can win seats on much lower primary votes than major party candidates, has significantly reduced the usefulness not just of terminology like 'safe seats', but of the so-called two party preferred national vote share and even the significance of 'national swings'.