Liberal MPs and senators will meet in Canberra on Wednesday to thrash out a final position on climate and energy.
After the Nationals agreed to dump net zero by 2050 as a policy, the Liberals have faced calls to follow suit, placing pressure on Ms Ley's leadership of the party.
Coalition frontbencher Angus Taylor was last week seen dining in Canberra with a splinter group of conservatives who have been vocal in their criticism of net zero, including West Australian MP Andrew Hastie.Â
It sparked rumours Mr Taylor or Mr Hastie might be manoeuvring to challenge Ms Ley pending the outcome of this week's climate policy discussions.
Mr Taylor brushed off suggestions he was planning a coup but was less than effusive in his support of his leader.
"Well, that's just not right," he told Nine's Today program on Tuesday.
"I'm focused on making sure we've got the policies we need coming together to hold this government to account and to be contestable at the next election."
While shadow attorney-general Andrew Wallace said he backed Ms Ley's leadership, he also reserved praise for Mr Taylor.
"He has been outstanding in (the defence portfolio) and I really do think that he has been an exemplar as a potential leader," he told ABC TV.
Mr Taylor ran in the leadership ballot for the Liberals following the party's election loss in May, but narrowly lost to Ms Ley.
Mr Wallace said his shadow cabinet colleague had set an example as a "vanquished" leadership candidate.
"Angus has not done one thing that I have seen, privately or publicly, that would confirm to me that he is trying to destabilise Sussan Ley."
Opposition communications spokeswoman Melissa McIntosh said she had always backed Ms Ley as leader but played down suggestions of being involved as part of a future Liberal leadership ticket.
"I don't think there's anything wrong in having ambition in the future, but that doesn't mean that you're going to challenge or do anything about it right now," she told Sky News.
"I'm happy where I am, and my laser focus is on being a strong voice for the people of my community."
Any move to weaken Australia's targets would be in breach of the Paris accord, University of Queensland climate and environmental law expert Justine Bell-James said.
"Under the Paris Agreement countries have to make these pledges every five years," Professor Bell-James told AAP.
"Because of this mechanism that they call the ratchet mechanism, each successive one needs to be an increase in ambition."
Latrobe University climate law expert Julia Dehm agreed, saying a future government would "certainly" be in breach of the Paris agreement if it went back on its promises.
Dr Dehm said a ruling from the International Court of Justice in July that all countries had a legal obligation to tackle the "urgent and existential threat" of climate change was an additional barrier to watering down Australia's climate targets.
"There is the potential for states to take Australia to the ICJ alleging that it hasn't fulfilled its international climate obligations," she said, adding a weaker emissions reduction goal would also cause reputational damage for the government.
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