The New South Wales government has been accused of failing to act on promises to offer better protection to whistleblowers who approach the state’s anti-corruption watchdog.

Last week, Guardian Australia revealed that two western Sydney council rangers were sacked after blowing the whistle on allegations they were directed to stay away from developments owned by a local councillor.

They had passed the information on to a councillor, the Independent Commission Against Corruption (Icac), and later to a public inquiry, and are now launching a rare test of the state’s whistleblower protections through litigation in the NSW district court.

Almost two years ago, the state government promised to strengthen whistleblower protections in the public interest disclosure act. It also pledged to introduce stronger protections for whistleblowers who provide information voluntarily to the Icac.

Currently, those who volunteer information on corrupt conduct that the Icac is not investigating do not receive automatic protection.

The government was acting on recommendations from dual, government-controlled parliamentary committees.

But no legislation has yet materialised.

Labor and the Greens are now pushing for reform. The shadow attorney general, Paul Lynch, said the government had ignored the recommendations for too long.

“The government’s dilatory approach to this important area of reform merely increases risks for whistleblowers,” he said. “This is too important an issue for such indolence.”

The Greens are planning to introduce their own bill this month to extend the Icac protections. Icac itself had called for such protections in 2014, forming the basis for a Greens bill that was voted down in 2016.

Jamie Parker, the NSW Greens anti-corruption spokesman, said the reforms would have protected the two Auburn parking rangers who were sacked for blowing the whistle.

“These rangers have disclosed to the Icac an alleged order to give preferential treatment to elected members of a local council, been suspended and then terminated,” Parker said. “The law I am proposing would seek to ensure that they have the full protection of Icac and aren’t forced to pay a huge personal cost for doing what is right.

“The Icac cannot effectively investigate corruption in NSW if witnesses are too scared to report.”

A spokesman for the special minister for state, Don Harwin, said the government was committed to ensuring whistleblowers were properly protected. He said the government was currently preparing a bill and “anticipate it should be introduce into the parliament by the end of the year”.

“We support making it simpler for public officials to make disclosures and improving protections for those who suffer detrimental action,” he said.

But Parker said the government had known about the deficiencies in whistleblower protections since 2016, when he introduced his first bill.

“The current laws have a chilling effect on whistleblowers who are forced to weigh up their instinct to report against the prospect of losing their job or being sued,” he said.