Nepean by-election tests Liberal and One Nation support in Victoria ahead of state election
Consensus Summary
The Nepean by-election on Victoria’s Mornington Peninsula on May 2, 2026, serves as a critical test for Liberal leader Jess Wilson and One Nation’s rising influence ahead of the November state election. Triggered by the resignation of Liberal deputy leader Sam Groth in February, the seat has been held by the Liberals since 2018, but polling shows One Nation leading in primary support with 36% compared to the Liberal/National coalition’s 28%. The by-election is notable for Labor’s decision not to contest the seat, leaving the field open to Liberals, One Nation, and independents. Anthony Marsh, a local mayor and former Air Force officer, represents the Liberals, while Darren Hercus, a small business owner, leads for One Nation. Early voting shows strong turnout, with 17,691 votes cast before polling day. The Liberals face internal divisions and a fragmented political landscape, with One Nation gaining traction among older voters and independents targeting disaffected Liberal supporters. A hung parliament is possible in November, making the by-election results a key indicator of shifting voter preferences.
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Key details reported by multiple sources:
- The Nepean by-election is being held on May 2, 2026, with voting from 8am to 6pm
- The seat of Nepean is located in the Eastern Victorian Region on the Mornington Peninsula
- The by-election was triggered by the resignation of former Liberal deputy leader Sam Groth in February 2026
- Liberal candidate Anthony Marsh is a former Mornington Peninsula Shire Mayor and Air Force officer
- One Nation candidate Darren Hercus runs a fabrication business in Safety Beach and focuses on small business and local jobs
- Labor is not contesting the Nepean by-election, leaving the seat contested by Liberals, One Nation, and independents
- Roy Morgan polling shows One Nation leading in primary support in Nepean with 36% ahead of the Liberal/National coalition on 28%
- The seat of Nepean has been held by the Liberal Party since 2018, with a 50.54% two-party preferred vote in 2022
- As of 10am on May 1, 2026, 4,910 postal votes and 17,691 early votes had been returned in the Nepean by-election
Points of Difference
Details reported by only one source:
- Liberal leader Jess Wilson is campaigning in Nepean, with a viral social media stunt involving unauthorised roadworks that led to an investigation by Victoria’s transport department
- Sky News poll in April 2026 showed One Nation as the most popular party in Victoria with 26% of the primary vote in a federal election
- Roy Morgan polling shows statewide Victorian support split as: Labor 25.5%, One Nation 24.5%, Liberal-National Coalition 24%, and 26% for other parties (Greens 13.5%, Independents 8.5%)
- Premier Jacinta Allen is accused of 'running scared' ahead of the by-election due to Labor not contesting the seat
- The Nepean by-election is the third in Victoria since 2023, with previous costs being $4,219,000 for Prahran and Werribee (2025) and $680,485 for Mulgrave (2023)
- One Nation founder Pauline Hanson stated Victoria is a 'basket case' and claimed new membership is surging from the state
- Nepean has a median age of 53, the oldest electorate in Victoria, with low workforce participation and many retirees
- Independent candidate Tracee Hutchison, backed by Independents of Mornington Peninsula, is targeting traditional Labor voters in areas like Dromana, Rosebud, and McCrae
- Former independent Ben Smith won 47.7% of the two-candidate preferred vote in the overlapping seat of Flinders in 2025, suggesting potential independent support in Nepean
- The Liberal Party has been internally divided, with Sam Groth’s sudden exit and Anthony Marsh’s late preselection causing local unrest
- The Liberals need to flip 16 seats with margins of 7.5% or more to win the November state election, making Nepean a key test
Contradictions
Conflicting information between sources:
- Newscomau states One Nation leads in primary support in Nepean with 36%, while ABC does not provide specific polling numbers for Nepean but notes One Nation is gaining support in older, non-metro areas
- Newscomau claims the Liberal Party won Nepean with 50.54% of the vote in 2022, while ABC notes the Liberals won over two-thirds of the two-party preferred vote in affluent areas like Sorrento and Portsea but were less dominant in Dromana, Rosebud, and McCrae
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