Prime Minister Malcolm Turnbull will face a showdown over the merits of a proposed clean energy target when government MPs meet on Tuesday.
The coalition partyroom on Tuesday is expected to discuss the government's position on Chief Scientist Alan Finkel's energy review released last week.
The report has sparked debate within government ranks over the role of coal under Dr Finkel's recommended clean energy target, which would require a proportion of electricity each year to come from generation below a set emissions level.
Liberal backbencher Craig Kelly says he would not support a benchmark emission target of 0.6 tonnes per megawatt hour - the level used by Dr Finkel to model economic effects - while former cabinet minister Eric Abetz hit out at what he labelled "creative assumptions" in the report.
Labor opposition's climate spokesman Mark Butler said the same old toxic internal divisions in the coalition were re-emerging.
"Malcolm Turnbull tomorrow, at his party room meeting, needs to pull his party into line - particularly senior Liberals like Tony Abbott, who are clearly trying to wreck this process before it even begins," he told reporters in Adelaide.
Dr Finkel insists his proposed emissions reduction reforms would not block new coal projects, saying those decisions will be up to governments.
"There is no aspect of allowance or permission here. Permission comes from government. Permission is not decided by the clean energy target at all," Dr Finkel told The Australian on Monday.
Where that level is set - a task Dr Finkel left up to politicians - could effectively rule out coal generation unless it uses the newest technology.
Energy policy experts say this is an important strategic shift from focusing on pricing or suppressing emissions to the economics of building a cleaner energy grid.
Grattan Institute energy program director Tony Wood says that shift means the market will determine which technology is cheapest.
"If it turns out that a clean coal plant with or without CCS (carbon capture and storage) is actually commercially viable when the emissions intensity is considered, then there will be investors who will build those plants," he told ABC radio.
"It may not be likely, but this will test the commercial viability of the very coal technologies people would like to support."
Australian Energy Council chief executive Matthew Warren said old coal-fired generators didn't have to be forced out because they were leaving faster than they could be replaced.
Mr Warren cautioned the only way forward was to have bipartisan support for the final policy position.
Greens leader Richard Di Natale was scathing of the plan, which he says will leave Australia still generating power from coal and gas until 2070.
"The problem is that because the climate debate has been so toxic I think there's a sense that any plan is better than nothing," he told ABC radio.
