I often hear claims about how the British Labour Party is now the largest party in Western Europe with the number of new members cited. The numbers are impressive but also make me wonder how many members of Australian Labor Party are there and how it compares to the past. It is hard to know because membership numbers are a closely guarded secret.

Currently, the only state with available figures is New South Wales. It is only because New South Wales Electoral Commission provides details as part of the electoral disclosure regime. Registered political parties are required to disclose funds raised from membership fees and subscriptions. However, beyond New South Wales, there is no requirement for party membership numbers to be published.

The most recent official source for Australian Labor Party rank-and-file membership numbers is the 2010 National Review.

It provided an overall indication of party membership across Australia between 2002 and 2010 but it did not delve into historical membership figures in the 20th century. Without that data, we do not know how large a decline there has been since the heyday of party membership.

The best available estimate of ALP rank-and-file membership numbers from the 20th century is from Andrew Scott’s 1991 book Fading Loyalties. Based on what fragments of data he could gather, Scott concludes that ALP membership peaked in the decade following the Second World War at around 75,000 and fell to less than 45,000 following the Split and never recovered (though there was some growth until Whitlam). While there was some growth in South Australia and Western Australia afterwards but it could not compensate for declines in New South Wales and Victoria.

The problem with national figures, however, is they hide changes in state branches which can be significant over time.

The book Machine Politics in the Australian Labor Party provides rank-and-file membership numbers for each state and territory branch in 1980. While an approximation, it shows that even though the Australian population has grown by 67%, overall ALP membership numbers are stagnant.

The most recent publicly available figures, broken down by state branch, are from 2015 (though there is a national figure of 53,550 at the end of 2017). These were leaked to The Australian around the time of the National President ballot.

From this comparative table, we can see that while national ALP membership has been fairly flat in raw numbers over the past three decades, there have been shifts in membership numbers within each state and territory branch.

It is clear from all these party membership figures that the ALP has never been a mass political party though some state and territory branches such as Queensland and the ACT are doing much better than others like SA and Tasmania. Why is something worth further investigation.