Ok...I can see I need to research more about "Preferential voting" and 'proportional representation'.

I have posted here before that our (the US) 2 party system can never accurately reflect the actual scale of opinions and affiliations of the electorate. The only system I have read much about is Israel's, where many parties form alliances, but many have seats in the Knesset.

It would require quite a major restructuring for us, and I wouldn't take bets on either current party being willing to change, since both would lose 'some' influence that way.

A brief reading tells me that Preferential voting would be easier to add, rather than changing the entire setup of Congress.