Australia's commitment to slash carbon pollution by up to 25 percent was in jeopardy Sunday, as rebel opposition politicians refused to support the deal.
Prime Minister Kevin Rudd wants legislation on an emissions trading scheme, which would cut greenhouse gas emissions by between five to 25 percent from 2000 levels by 2020, in place ahead of a global summit on climate change in Copenhagen.
But it is uncertain whether the bipartisan deal, which was agreed by the governing centre-left Labor Party and opposition conservative Liberal Party, will pass the Senate after several rebel Liberals said they would oppose it.
"We should delay it and if that means talking it out, that means talking it out," former Liberal minister Kevin Andrews said.
His colleague Senator Nick Minchin said he too would oppose the law, arguing that Australia should not make firm commitments until other nations put theirs on the table at the talks in Copenhagen set to begin on December 7.
"It's about what's the right thing to do for Australia and in my view the right thing to do for Australia is not to rush this legislation through the parliament this week," he said.
The Senate rejected earlier legislation in August and on Friday missed a deadline for the passage of the laws, sparking deep divisions among the Liberal Party which has committed to supporting the bill.
If the Senate rejects the bill again, Rudd could call a "double dissolution" election.
But Deputy Prime Minister Julia Gillard said Sunday that the government was "not interested in an early election" and wanted the legislation passed in Monday's extraordinary parliamentary session.
"What we are interested in is delivering action on climate change because we understand the consequences of delay. Delay is denial," she told the Australian Broadcasting Corporation.
Failure to pass the cuts would be deeply embarrassing for pro-green Rudd ahead of the Copenhagen talks, with the prime minister saying it would jeopardise Australia's ability to be "fully active in the negotiations."
Australia, the developed world's worst per capita polluter, is responsible for about 1.5 percent of global emissions.