The son of former prime minister Malcolm Turnbull says he's "involved" in the campaign by ex-Liberal MP Julia Banks to unseat Health Minister Greg Hunt at the federal election.
Alex Turnbull made the admission to The Sydney Morning Herald and The Age in a report published on Friday.
"I'm involved, I'll leave it at that," he said.
But he denied his father was also involved.
Liberal renegade Ms Banks has vowed to put climate change and gender equality front and centre when she runs against anti-Turnbull MP Mr Hunt in the Victorian seat of Flinders.
The electorate takes in much of the Mornington Peninsula where Ms Banks has owned a property for the past 20 years.
The lawyer, who will stand down from her current seat of Chisholm, defected to the crossbench after Mr Turnbull was toppled as Liberal leader in August.
"Effective climate change action policy is an urgent imperative," she said in a statement on Thursday.
"In relation to refugees, I'll always be an advocate for a humanitarian approach.
"And I'll continue focused advocacy on gender equality, fair and equitable workplace cultures and equal representation of women in leadership positions."
Ms Banks has been the member for Chisholm in Melbourne's southeast since 2016, when she became the only member of the federal coalition to win a seat from Labor.
Opposition Leader Bill Shorten says he wouldn't want to be Mr Hunt.
"The chickens have come home to roost in the form of the very formidable Julia Banks," he told reporters in Brisbane.
"Her running in Flinders is the ultimate sign of the failure of the prime minister's authority over his own party."
But Mr Hunt, who has held Flinders since 2001, downplayed suggestions the challenge stems from his role in ousting Mr Turnbull.
Prime Minister Scott Morrison believes Mr Hunt will hold onto the seat.
"Greg Hunt has worked like a Trojan for his community since the day he was elected in the seat of Flinders," he told reporters in Brisbane.
