Tasmanian Liberal Bridget Archer says she is willing to again vote against her party in support of the government's climate change bill.
The federal government will introduce a bill to parliament on Wednesday that would formalise a target to reduce emissions by 43 per cent by 2030, and require the government to report its progress.
Climate Change Minister Chris Bowen said the legislation would also oblige the Climate Change Authority to advise government on future targets, including for 2035.
The government is still negotiating with the Greens to win its support, which is needed for the bill to pass the Senate, but it has agreed to tweak the bill to spell out that the 43 per cent target is a minimum standard, not a cap.
"We have shown we are prepared to take constructive suggestions on board," Mr Bowen said.
Ms Archer's vote in the lower house is not needed to pass the bill, but the Bass MP said she was prepared to cross the floor anyway, with a view to ending a decade of political warring on climate.
"I haven't looked at the detail of Labor's legislation yet, and our party room hasn't had the opportunity yet to discuss it, [but] ending the climate wars is really the perspective I am approaching this from," Ms Archer told ABC Radio.
"I am a proud member of the Liberal Party. But in the hierarchy, if you like, of who you represent first and foremost, it's the people of Bass."
Ms Archer drew attention earlier this year when she crossed the floor to vote against her Coalition colleagues on an anti-corruption commission bill, and later to extend discrimination protections to transgender students.
Mr Bowen said the Liberal Party was out of step with industry and the community.
"The Liberal Party — at least the leader of the Liberal Party — seems to have not received the memo from the Australian people on May 21 that it's time to end the climate wars," he said.
"Liberals of good conscience can consider their position when the vote comes to parliament."
Greens hold out on critical support
The government can pass its climate target bill through the lower house without support from Ms Archer or other MPs, but it will need external support to succeed in the Senate.
Greens leader Adam Bandt, whose party's support will be critical if the Liberals do not back the bill, said he was still negotiating with the government.
"Our hope is that we can end up with a situation where we can improve the government's bill and pass it," Mr Bandt said.
Mr Bandt said the Greens were concerned about a "weak" 43 per cent target that was limited because Labor's model relied on keeping coal-fired power in the system.
The party is continuing to push for no new coal mines or gas plants being opened.
"We don't want to be in a situation where the parliament might pass a bill to cut Australia's bill on Monday and then on Tuesday that good work gets undone when the government opens a big new gas project that would blow even that weak target out of the water," Mr Bandt said.
But Mr Bandt said the government had agreed to spell out in the legislation that the 43 per cent emissions reduction target was a "floor, not a ceiling" to ensure there were no obstacles in the future to possibly raise it further.
Prime Minister Anthony Albanese said the 43 per cent target was a minimum standard, but said it was also an achievable target.
"We actually need to have a plan to get change. You can't just come up with a figure or come up with a sort of thought bubble," he said.
"I say to both the Coalition but also to the crossbenchers that Australians and indeed the business community in particular wants this parliament to move on from the old days of division."
Ms Archer said she would welcome the 43 per cent target being considered the minimum.
"I think we can fixate on the number, and that's part of the climate wars if you like … but I think we need to shift that conversation to taking some action," she said.
