NSW Prime Minister Chris Minns warned that failure to pass his controversial workers’ compensation legislation would cast a $20 billion loophole in the state budget as Labor tried to attract a coalition of conservative cross-benchers to pass the bill.

The Prime Minister said in Parliament that if changes to reduce psychological injury claims fail to pass, NSW taxpayers will need an additional $20 billion to fund the public service portion of the scheme.

He also warned that businesses will increase premiums by 36% over three years to fund private sector plans.

Sources told Australia's Guardian Australia that the shooter and the Fishermen and other right-leaning MPs lobbied heavily, including former state MPs Mark Latham and Rod Roberts, legalizing marijuana MP Jeremy Buckingham and liberal John Ruddick.

The opposition will move on Thursday to send complex bills to inquiries. Opposition leader Mark Speakman described it as “unreasonable” and “brutal”.

The opposition hopes that 15% of the damage status quo can be compensated instead of the 30% proposed by the government.

He said the opposition offered amendments that could save some savings, such as tightening the definition of psychological harm due to bullying or “infeasible” claims arising from “overwork requirements,” but the coalition would not be satisfied with the barrier threshold.

A 15% barrier means a person struggles with daily tasks and needs to be reminded of their hygiene needs. Experts say 30% of the damage to the entire person is so high that it makes it almost impossible for people to make considerable compensation for psychological harm.

Shadow Treasurer Damien Tudehope warned that the government is seeking to declare a leap in products in other policy areas, which is important for them.

He said the public has a strong opinion on the morality of this approach.

Two days after the government released its workers’ compensation legislation, Minns said many expressed support for the bounty program proposed by the shooting party in its wildlife conservation bill.

The bill will create new protection of hunting rights and propose a series of changes, including the enjoyment of "hunting rights" and the recognition of hunting as a conservation management tool.

Minnes has previously denied any agreement with the shooter to support other legislation.

Conservation teams and scientists condemn hunting recommendations for wasting taxpayers’ money.

As debate on the bill began in the House of Lords on Wednesday, a scientist-led biodiversity committee wrote to MPs to warn that the legislation, if passed in its current form, would “destroy the management of invasive species across the state, resulting in poorer environmental and agricultural outcomes.”

Conservationists fear the bill will be a tool to promote recreational hunting and management of invasive species as the benefit of games, rather than pushing wildlife populations through control procedures.

The Invasive Species Council and other groups also expressed concern that the proposed authorities have similarities with the resolved Games Committee, which was repealed in 2013 and that hunting interests will dominate the voting structure proposed by the authorities.

"Recreational hunting is not protection. It rarely brings environmental benefits and, in many cases, actively hinders professional control programs."

There seems to be an exception for motorists who test positive when using medical marijuana, a policy promoted by Buckingham and the Greens.

Unions, legal and medical experts strongly criticized the government's attempt to cut psychological injury claims, warning that a 30% threshold would make it nearly impossible for people to file a claim.

They urged the government to focus first on preventing and educating employers to deal with psychological injuries rather than cutting off compensation.

NSW union secretary Mark Moryy said the results will be just for transfer to welfare and health systems.

The compensation for injured civil servants comes from the Ministry of Finance Trust Fund (TMF), which has been under tremendous pressure due to natural disaster funds last year.

The full scope of the fund's deterioration will be revealed in the June 24 budget.