Voting in Australia's federal elections has been compulsory since 1925...but betting on political markets is a much more recent thing.
For the House of Representatives, a preferential ballot system has been in use since 1919, in single-member seats. For the Senate – the proportionally representative upper house – a single transferable vote system has been in use since 1949, with optional group voting tickets since 1984. The election will be conducted by the Australian Electoral Commission (AEC).
Bookmakers like Sportsbet
offer markets on Australian politics including elections, referendums, budgets, as well as UK political betting, US political markets and when government legislation will be introduced for things like same sex marriage.