Labor's signature bill would establish a state 2050 net-zero emissions target and an independent commission to review and report annually on the government's progress.
It will also enshrine a 2030 goal of a minimum 50 per cent cut in greenhouse gas emissions on 2005 levels.
But MPs who will be critical to the passage of the bill will on Friday call for improvements, pointing to official projections showing the state is already on track to cut emissions by 55 per cent by 2030.
"There is genuine concern in NSW that we're not doing what we should be," Greens climate spokeswoman and former environmental lawyer Sue Higginson told AAP.
"We need ambition, courage and to take a step forward."
Australia's former chief scientist Penny Sackett told a parliamentary inquiry in October that the state had to move faster.
She also called for a 2035 target in the bill.
"These emissions cause significant harm to the people and environment of NSW," Professor Sackett said.
The committee inquiry report will be released on Friday.
The government's bill would establish an independent commission to review and report annually on the government's progress.
As well as being part of Labor's platform, a legislated target was a rallying cry for teal candidates in the last state election.
But, at a minimum, the Greens, Animal Justice Party and independents want the current bill amended to ensure the Net Zero Commission is free from undue influence from the fossil fuel industry and can advise on coal and gas projects.
The bill also needs to impose a responsibility on the government to reach the targets and oblige the government to act consistently with the guiding principles for climate action, the MPs argue.
NSW Environment Minister Penny Sharpe has previously described each target as "a floor, not a ceiling" and said the government would keep the 2035 target set by the previous coalition government.
"The whole point of legislating the targets and having the Net Zero Commission is it'll track how we're doing and, if we need, to make sure that we get there," she told reporters in October.
To pass any legislation opposed by the coalition, the Minns government requires the support of two crossbenchers in the lower house and six in the upper house.