The Australian Electoral Commission conducts a two-party-preferred vote in every seat, which is a count between Labor and the leading Liberal or Nationals candidate. In seats where the two-candidate-preferred vote is not Labor vs Coalition, they do the count later. With 35 seats now “non-classic”, the AEC needs to conduct those notional 2PP counts in more and more seats.
This means that it is possible to calculate the national 2PP. It also means that it is easier to make comparisons over time that cover the whole country. 2CP counts vary from seat to seat so can’t easily be compared, and 2CP pairings often change in a seat. Not so for 2PP.
The national 2PP count has been stalled for some time now, with 149 seats finished their count. But the Bradfield count has barely started. I asked the AEC about this, and it appears that the count remains on hold while they wait to find out if there will be a court case. So it is possible it could be quite some time before Bradfield’s 2PP is determined. So for this post, I wanted to look at the data to come up with some estimates of the likely 2PP, and come up with a number I can use for some other analysis I’d like to do.
The first thing worth noting is that there is very clearly a relationship between the 2PP and the 2CP in these sorts of seats. For this analysis, I’m going to look at data from the urban seats where teals have beaten Liberals in 2022 or 2025: Bradfield, Curtin, Goldstein, Kooyong, North Sydney, Mackellar, Warringah and Wentworth.
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This chart shows every polling place in these seats in 2022 and 2025, excluding Bradfield 2025. While there is a high correlation (about 0.85), the independent 2CP is usually higher than the Labor 2PP. The black diagonal line shows the point where the two are identical. Very few booths have a higher 2PP. But that gap is not always the same.
This next chart compares the 2CP and 2PP in each contest.
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Warringah, Mackellar and Wentworth had a 2CP 10-12% higher than the Labor 2PP in 2022. On the other hand, the gap was just 2.3% in Bradfield in 2022, 4.2% in North Sydney in 2022, and gaps of 3-4% in Goldstein and Kooyong in 2025.
This could imply a Labor 2PP of 40%, or a 2PP of 47-48%. So what is more likely? And what explains the differences.
I think a big part of the story is the make-up of that 2CP and 2PP. Votes cast for the independent will all flow to the independent in the 2CP, but some of them won’t flow to Labor on the 2PP. Conversely, votes for Labor will partially leak on the 2CP, but not on the 2PP.
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This does seem to be part of the story. Bradfield and North Sydney have tended to have higher Labor primary votes compared to other teal seats, and lower primary votes for the teal independents.
So I wanted to come up with a metric to measure this dynamic, and how it might relate to the difference between 2PP and 2CP. I came up with two that seem to both work: the ratio of teal to Labor primary votes, and the proportion of the teal 2CP that started as a teal primary vote. I’ve gone with the second one but they seem to produce similar results.
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If you plot out the independent primary share of the 2CP, and compare it to the 2CP-2PP gap, there seems to be a strong relationship. Such a chart implies that Bradfield in 2025 would have a gap of about 4.8%.
The other measure worth considering is the proportion of preferences that flow to the ALP on the 2PP.
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In all of these contests, Labor has never polled less than 65% of the 2PP preference flows, and have gotten as high as 79.4% in Kooyong this year.
If the Labor 2PP was to be 45.2% as the previous chart suggested, that would be a Labor preference flow of 59.8%, well below other seats.
If Labor gained a 65% preference flow, that would give them a 2PP of 47.4%. A 70% preference flow would give them 49.5%, almost as good as the independent 2CP.
So I think we should go somewhere between these numbers:
- Judging by the independent primary vote share of the 2CP – 45.2%
- Judging by 65% Labor 2PP preference flow – 47.4%.
So I’m going to go with a figure of 46.3%. I don’t have a great deal of certainty on this – it’s entirely possible the number will be even higher, but this will do.
This would bring Labor’s national 2PP down from the current AEC figure of 55.28% to 55.23%. This is consistent with the ABC projection of 55.2%.
It would also mean that Bradfield would have a swing to Labor of 2.43%, compared to 4.2% in Mackellar and 5.3% in Warringah. So perhaps that is a sign that I’ve estimated the Labor 2PP a bit low, but I’ll stick with it.
It may be a few days before I get around to continuing this analysis – I will be travelling to Canberra tonight for a conference on the federal election book tomorrow, and at some point I’d like to do a podcast about Tasmania – but I will be coming back to this topic to look at how 2PP in each seat has shifted over the last two decades.