NSW parliament's upper house has voted to give the corruption watchdog an extra $7.3 million, as a debate continues over the funding model for the body.
The government will now be forced to vote on the funding boost in the lower house.
Greens MP David Shoebridge, who introduced the motion on Tuesday evening, said the money would restore the Independent Commission Against Corruption to what its budget would have been if funding had tracked with inflation.
ICAC told a parliamentary inquiry last year that its annual funding had been below inflation for most of the 30 years since its inception, leaving it with a $7.2 million budget shortfall.
All non-government members of the Legislative Council on Tuesday evening sided with the Greens' amendment to the parliamentary budget bill to give the anti-corruption body the funding boost.
The $7.3 million figure represented 0.0007 per cent of the overall expenditure in the 2020/2021 budget, Mr Shoebridge told AAP on Wednesday.
But the money is not guaranteed to reach ICAC, as the amendment requires the approval of the lower house.
Premier Gladys Berejiklian told reporters on Wednesday she would consider the amendment when it reached the lower house.
The Legislative Assembly will have a special sitting on Friday after the upper house passed an amended energy bill following a marathon sitting to deal with One Nation-proposed amendments.
The lower house can vote against the ICAC amendment, which would send the parliamentary budget bill back to the upper house for another vote.
Labor and the Greens also want a fundamental revamp of ICAC's funding model, arguing that it has been starved of the funds it needs to run complex investigations.
They say the watchdog's funding needs to be independently determined. Currently, ICAC's funding is generally signed off by cabinet's expenditure review committee.
Last month, an auditor-general report said the current funding model threatens ICAC's independence, given funding decisions are made by people who might be subject to investigations.
Ms Berejiklian said the government was still considering the report which came hot on the heels of her own appearance at ICAC, where she admitted to having a long-running, secret affair with Liberal MP Daryl Maguire, who was being investigated by the watchdog.
Opposition Leader Jodi McKay said it was crucial ICAC was properly funded and Ms Berejiklian had kept it "on a drip feed, forcing it to repeatedly ask for more resources".
"On many of those occasions, no additional funds were provided," Ms McKay said.
Ms Berejiklian said the government had increased the recurrent expenditure for ICAC funding in excess of 20 per cent in this year's budget.
Mr Shoebridge said in parliament on Tuesday that the budget contained a modest increase in funding for ICAC, but went nowhere near making up the shortfall the anti-corruption body identified.
"Let alone providing additional funding, because that shortfall has been robbing ICAC year in and year out," he said.
Australian Associated Press