Resources Minister Keith Pitt has made it clear the Nationals will fight against adopting a target of net zero emissions by 2050.
Prime Minister Scott Morrison appears to have used an overseas trip to lay the groundwork for adopting the climate target later in 2021.
But back home, Mr Pitt has signalled the Nationals are not on board.
He said Australia had not committed to the target and doing so would require agreement from the junior Coalition partner.
Mr Pitt said agreement had not been sought and the Nationals had not even been asked.
“I think they would be unsupportive,” Mr Pitt told ABC radio on Thursday.
In a joint statement after last weekend’s G7 summit, world leaders said continued global investment in unabated coal power generation was incompatible with keeping global warming to 1.5 degrees.
The statement was not designed to single out Australia but highlighted Mr Morrison’s outsider status on climate change.
It also made it more difficult for him to continue resisting calls to commit to achieving net-zero carbon emissions by 2050.