The federal government is expected to secure a parliamentary win for its signature climate action bill in the next 24 hours.
A government motion in the upper house to be moved by Finance Minister Katy Gallagher will push the debate deep into Wednesday night to allow all senators to speak on the bill if they wish.
The motion paves the way for the Senate to vote on the bill and its proposed amendments on Thursday, after it passed the lower house on August 4.
Independent senator David Pocock has secured some amendments to the bill which he will move alongside the Jacqui Lambie Network, telling the Senate while Labor's 43 per cent emissions reductions target wasn't high enough, he would vote for the legislation.
"While I'd like to see more ambition, climate scientists would like to see more ambition, millions of Australians would like to see more ambition - 43 per cent is certainly an improvement on where we were 12 months ago," he said.
Senator Pocock said he "won't let the perfect be the enemy of the good", speaking on the need to ensure the 2030 emissions reductions target and net-zero by 2050 is enshrined in legislation.
"This target will provide certainty to encourage the large scale investment that will be needed in the transition to renewable energy," he said.
"After more than a decade of climate wars we need to bank some gains."
Opposition Leader Peter Dutton has lashed out at the government's legislation, saying it would leave the country in a difficult position.
"Our concern is that when faced with economic headwinds, rising costs of living and energy shortages, some nations will not honour their emission targets including some of our competitor nations," he told a mining conference in Canberra on Wednesday.
"Labor's legislation will deny the government important policy options, placing Australia in an inflexible position, when all nations need flexibility to respond to the prevailing and volatile conditions."
Mr Dutton also criticised the government's safeguard mechanism, which would lower emissions for more than 200 of the country's biggest polluters.
He said the measure was a tax by stealth, saying the mechanism spoke to the government's distrust of industry.
The coalition remains opposed to the bill but it will likely pass after the government secured the vote of the Greens and crossbench senators.
Greens senator Sarah Hanson-Young indicated the bill would be passed on Thursday but chastised the government for potentially approving a new mine expansion alongside passing key climate legislation.
"We're on the brink of closing the debate and passing the government's climate legislation in the Senate," she told reporters on Wednesday.
"It will become law and this is happening at the exact same time as Environment Minister Tanya Plibersek has on her desk a request for the biggest expansion of a coal mine in NSW since Australia signed the Paris Agreement.
"Don't make a mockery of your new laws on day one. Send a message to the industry, to the market and to the Australian people you're serious about cutting pollution."
Senator Hanson-Young added she didn't buy the argument of the opposition that transitioning to net-zero faster and having more ambitious emissions reductions targets would increase the cost of living or kick up energy prices.
"The gas companies are gouging the market, it's the gas companies forcing Australians to pay exorbitant fees on their power bills," she said.
"Let's get serious about transitioning our energy sector to clean cheaper renewables so everyone can have cheaper power bills."
