Key Points
- Sussan Ley is facing a new test on the party's policies to deal with climate change.
- One of the Opposition leader's frontbenchers has threatened to move to the backbench over the issue.
- Another Liberal has criticised adopting net zero "at any cost".
A Liberal senator has warned the Coalition will face a "mass exodus" from its frontbench if it adopts a net zero policy without caveats, handing Opposition leader Sussan Ley a fresh test over the party's stance on climate action.
A day after Opposition home affairs spokesperson Andrew Hastie said he would leave the frontbench if the Liberal party pursues net zero by 2050, his colleague Jonathon Duniam also raised concerns.
"If we said net zero by any cost by 2050 I think you'll find there'd be a mass exodus," Duniam, the Opposition education spokesperson told Sky News on Tuesday.
He said Liberal members wanted to make sure the policy would not come at a cost to Australian households and businesses to meet those targets.
"While they'll (Labor) tell us how much it costs not to act, they won't tell Australians how much it costs to act."
But Duniam said a revolt would be unlikely to occur because net zero at any cost would not be something the party would "countenance".
"Our party room, I'm pretty certain, based on the conversations I've had, including with our own leader, Sussan Ley, is that adopting net zero at any cost is bad policy."
"Net zero at any cost is something that only stupid people would pursue."

Liberal MP Jonathon Duniam (right) says his colleague Andrew Hastie (left) is "a man of integrity and one who is consistent about his views" on climate policy. Source: AAP / Mick Tsikas
"I've nailed my colours to the mast," he said.
The latest debate within the Coalition over net zero was sparked after the release on Monday of the National Climate Risk Assessment, which showed no Australian community will be immune from climate risks that it said will be "cascading, compounding and concurrent".
The report said hazards such as coastal floods, heatwaves, droughts and bushfires are projected to occur more frequently, more severely, and often at the same time, with the report warning Australia — a land mass that warms much faster than oceans — will "reach a given warming level much faster than the globe".
Responding to the report, Nationals MP Matthew Canavan, a sceptic of climate policy, said it was scaremongering.
"It reads like the Book of Daniel, not a government report," he said, referring to the Old Testament text, which references the end times.
"I like government reports that are sober and reasonable, not dramatic."
Labor frontbencher Pat Conroy rejected Canavan's claims, telling ABC Radio National breakfast on Thursday that Nationals senator was "symptomatic of an opposition that’s woefully out of place, out of touch with both the science and the views of the Australian people".
In July, Nationals MP Barnaby Joyce introduced a bill to scrap Australia's net zero emissions reductions goal.
Queensland's Liberal National Party, which includes federal members of the Coalition, passed a resolution to abandon net zero by 2050 at its annual convention in Brisbane over the weekend.
Recent data released by the government found Australia is tracking well to meet its 2030 target to reduce greenhouse gas emissions by 43 per cent from 2005 levels.
Emissions have fallen by 1.4 per cent in the year to March 2025, meaning about 440.2 million tonnes were released in that period — about 28 per cent below 2005 levels.
— With additional reporting by the Australian Associated Press