The Victorian state election in November looms as one of the most consequential in recent memory. Against that backdrop, the recent by-election in the seat of Nepean has been dissected as an early signal of voter sentiment. On the surface, the result appears straightforward: the Liberal Party retained the seat. But beneath that headline lies a far more complex and potentially telling political story.

Nepean, covering the Mornington Peninsula, has long been considered a natural Liberal stronghold. The party has held the seat for most of the past four decades, interrupted only briefly by a Labor victory in 2018 before returning to Liberal hands in 2022 . In that context, a Liberal hold is not unexpected.

Yet this by-election was never going to be a simple confirmation of the status quo.

The Liberals, represented by candidate Anthony Marsh, secured victory and maintained the seat following the resignation of former MP Sam Groth . On a two-party-preferred basis, the result was strong — even improving on previous margins. But the primary vote told a different story.

Reports indicate a notable drop in the Liberal primary vote — a swing against the party — even as it retained the seat through preference flows . In practical terms, this means fewer voters chose the Liberals as their first preference, but enough preferences from other candidates flowed back to deliver the final result.

That distinction matters.

In modern elections, primary vote is often the clearest measure of direct voter support. A declining primary vote combined with reliance on preferences suggests a weakening base — even in a seat that remains safely held.

Compounding this trend was the strong performance of minor parties and independents. Pauline Hanson's One Nation polled strongly, capturing roughly a quarter of the primary vote in some estimates, while independent candidate Tracee Hutchison also drew significant support .

This fragmentation of the vote is perhaps the most important signal from Nepean.

It reflects a broader pattern emerging not just in Victoria, but across Australia: voters are increasingly willing to look beyond the major parties. Dissatisfaction — whether driven by cost-of-living pressures, infrastructure concerns, or political fatigue — is finding expression in alternative candidates.

The absence of Australian Labor Party from the ballot further complicates the interpretation. Labor chose not to contest the seat, effectively turning the by-election into a contest between Liberals, minor parties, and independents. This created space for protest votes and experimentation by the electorate.

As election analyst Antony Green observed, such a result cannot provide a complete guide to statewide trends precisely because one of the major parties was missing from the contest .

Even so, patterns can still be identified.

One of the clearest is voter volatility. The Nepean electorate, while historically Liberal, has shown a willingness to shift — Labor won it in 2018, the Liberals reclaimed it in 2022, and now the primary vote has fragmented again. This is not a static electorate. It is responsive to broader political and economic conditions.

Another signal is the growing influence of minor parties, particularly in outer suburban and regional areas. One Nation’s performance in Nepean mirrors trends seen in other recent contests, where the party has tapped into dissatisfaction with both major parties. Its ability to convert that sentiment into sustained electoral success remains uncertain, but its presence is now a factor that cannot be ignored.

There is also a strategic dimension for the Liberals. Retaining Nepean was essential — losing a traditionally safe seat would have been politically damaging ahead of November. However, the drop in primary support suggests that simply holding traditional territory will not be enough to form government. The Liberals need to win multiple additional seats to unseat the Allan government, and that requires not just preference flows, but genuine first-preference momentum.

For Labor, the by-election offers both reassurance and warning. On one hand, the government avoided a direct test in a marginal environment by not contesting the seat. On the other, the rise of minor parties and independents reflects the same voter dissatisfaction that can erode support in Labor-held electorates.

Beyond party strategy, the Nepean result points to a deeper structural shift in Victorian politics.

The era of predictable two-party contests is fading. Elections are becoming multi-candidate, preference-driven contests where outcomes depend as much on how-to-vote cards and preference deals as on primary support. This increases uncertainty and can produce outcomes that appear disconnected from first-preference voting patterns.

It also raises questions about the electoral system itself. Concerns have already been raised about preference arrangements and the potential for micro-parties to influence outcomes disproportionately . With multiple minor parties likely to contest the November election, these dynamics will be amplified.

So, did a signal trend emerge from Nepean?

Yes — but it is not a simple swing toward one party or another.

The real signal is fragmentation.

Voters are less loyal, more willing to experiment, and increasingly prepared to use minor parties and independents as vehicles for dissatisfaction. Major parties can still win — as the Liberals did in Nepean — but often with weaker primary support and greater reliance on preferences.

For the November election, this has clear implications.

Expect more three- and four-cornered contests. Expect preference flows to be decisive. Expect minor parties to play a larger role than in previous cycles. And expect volatility — seats that once seemed safe may no longer be immune to shifts in sentiment.

Nepean did not deliver a definitive verdict on Victoria’s political direction. But it did offer a preview of the terrain: more competitive, more fragmented, and far less predictable than in the past.

For voters, that means greater choice. For parties, it means greater risk.

And for November, it means the outcome is still very much in play.