Public servants looking to blow the whistle to the upcoming national anti-corruption watchdog will be given extra protections in a move the federal government hopes will sweeten the deal for crossbenchers.
Crossbenchers say they are "satisfied" with the promises so far but are awaiting further details, including what those additional protections will look like, once the bill is introduced to the lower house on Wednesday.
Following approval at a government caucus meeting on Tuesday, Attorney-General Mark Dreyfus said the bill would include additional protections for whistleblowers and that he hoped reforms to the public interest disclosure scheme would be passed by mid-next year.
"The legislation also provides strong protections for whistleblowers and exemptions for journalists to protect the identity of their sources," he said.
"The National Anti-Corruption Commission bill will have its own whistleblower protections, as is appropriate for Australian public servants and people working in the public sector, who come forward with allegations that the commission should look."
Mr Dreyfus said $262 million had been committed to establish and operate the oversight body over the next four years and a parliamentary oversight committee would scrutinise funding arrangements.
The design principles would include a broad jurisdiction, covering ministers, parliamentarians and their staff, statutory office holders, employees of all government entities and government contractors.
It will be independent of government with discretion to start inquiries on its own initiative or in response to referrals, including from government entities, contractors and the public service.
It will have retrospective powers and the power to hold public hearings "in exceptional circumstances and where it is in the public interest to do so".
The commission will be empowered to make findings of fact, including findings of corrupt conduct and refer findings that could constitute criminal conduct to the Australian Federal Police or the Commonwealth Director of Public Prosecutions.
In question time on Tuesday, Mr Dreyfus also confirmed an independent inspector would be appointed to oversee the watchdog's operations.
Independent MP Helen Haines, who has long advocated for a federal integrity body with teeth, said she had a number of "good faith" discussions with the Attorney-General but was looking forward to seeing the finer details on Wednesday.
"I'm quite satisfied that what I understand thus far is that his bill looks very similar to the bill I put to the Parliament around a broad definition of corruption and that it needs to be serious or systemic," she said on Tuesday.
"And that it needs to shine a light on whoever is endeavoring to corrupt public processes.
"I haven't seen the legislation. I need to go through it clause by clause, I'll be giving it due scrutiny. I'll be applying a lot of my time and effort on this. I want to see it right through to the finish line."
The Greens will be seeking to ensure the bill has a wide jurisdiction and that commission is give as broad a scope as possible to hold public hearings.
Justice spokesperson NSW senator David Shoebridge said his party was concerned the bill's wording might limit its ability to hold public hearings.
"There should not be these hard lines set by politicians who too often are wanting to protect other politicians from the scrutiny that comes from a public hearing," he said.
"This should be left up to the common sense and the discretion of the commissioner of the day."
Integrity experts welcomed details of the body but remained concerned about possible limitations on public hearings and whistleblower protections.
Eminent judge and Centre for Public Integrity chair Anthony Whealy said the Coalition's proposal - which did not allow open hearings - was steeped in secrecy and the government should not follow suit.
"Sunlight is the best disinfectant, and many corruption investigations would not be successful without public hearings," Mr Whealy said.
"In legal terms, 'exceptional circumstances' has no real meaning and it will act as a brake on the public interest test."
Transparency International Australia chief executive Clancy Moore added strengthened whistleblowing laws were essential to the body's success.
"To be clear, our whistleblowing laws need a complete overhaul. We need a centralised authority, a one-stop-shop to ensure whistleblowers are properly protected and listened to," Mr Moore said.
"Otherwise, searching for corruption can be like searching for a needle in a haystack."
- with AAP