The primary vote of both the Labor Party and the Coalition have been, on average, declining since 1977.
But things aren’t what they seem with the Coalition. The Liberal Party component has been flat to rising over the same period:
While the National Party component has fallen into a ditch:
As a result of the contracting major party vote, the minor party and Independent vote has been growing over the same period.
However, debate still rages over whether the 1998 One Nation driven high point for the minors was the pinnacle of the non-major party vote or merely a harbinger of things to come. While the minor party vote has been increasing on trend but declining of late – the proportion of preferences flowing to the ALP from the minor parties has been increasing.