The rules governing sexual assault trials are, once again, the subject of a push for change – this time as part of a campaign led by advocate Nina Funnell, and news.com.au which is owned by the same parent company as The Australian.

The campaign aims to prevent defence lawyers in sexual assault cases using subpoenas to freely obtain the private counselling records of complainants.

In fact, complainants are already significantly protected, thanks to an upheaval in sexual assault trials that’s unfolded since 1997.

That was the year in which the then NSW attorney-general, the late Jeff Shaw, introduced pioneering legislation creating the nation’s first sexual assault communications privilege.

This gives courts the power to prevent those accused of sexual assault from freely using subpoenas to gain access to every note and record about their alleged victims’ counselling.

NSW even introduced a specialised division within Legal Aid which provides free advice to rape victims about the sexual assault communications privilege.

Different versions of this privilege are now in force around the nation, mostly drawing on the NSW model, which is a form of qualified privilege controlled by a judge.

Tasmania provides the strongest protection for counselling notes: absolute privilege, which means they can never be accessed without consent even if they contain relevant evidence.

Queensland adopted a broad protected counselling law in 2017 but the effect in every state is much the same; the law no longer gives defence lawyers in sexual assault cases unfettered access to the counselling notes of rape victims.

The sexual assault communications privilege strikes a careful balance designed to favour victims of sexual assault when judges decide which counselling notes should remain private and which can be used as evidence.

In 2012, in a case known as Veitch, Justice John Basten of the NSW Court of Criminal Appeal explained that while “the balancing exercise is weighted against disclosure,” material that casts doubt on the veracity or reliability of a complainant “will militate in favour of disclosure where it could give rise to a doubt as to the guilt of the accused”.

The current system is not a free-for-all – and there is real risk associated with introducing Tasmanian-style absolute privilege in every jurisdiction.

Suppressing all counselling notes in all sexual assault cases would inevitably mean suppressing some evidence that could prevent wrongful convictions.

It would mean juries would be kept in the dark about an entire category of evidence. The balance of the current system would be abandoned.

Sooner or later innocent people would go to prison.

In NSW, counselling notes can only be subpoenaed with leave of the court, and once they are produced they go to a judge, not the lawyers for the alleged rapist.

It is a judge who then decides what is fit to be used in evidence and what must remain confidential.

That means judges are required to examine hundreds and sometimes thousands of documents before anything can be used in court.

Subpoenas for counselling notes will only be issued for material that has “substantial probative” value for use as evidence.

This is more restrictive than the normal rule that means subpoenas can require the production of material which has a “legitimate forensic purpose” regardless of whether it is for use as evidence.

But even if a subpoena does produce material that would be good evidence, judges will not allow it to become public if the public interest in the protection of confidences and possible harm to a rape victim outweigh the public interest in allowing the material to be used in court.

Jeff Shaw, and one of his successors as attorney-general, John Hatzistergos, created, defended and expanded a balanced form of privilege despite resistance from parts of the legal profession.

In 1999 the acting president of the NSW Bar Association, Ruth McColl, SC – who was subsequently appointed to the Court of Appeal – wrote to Shaw warning that the privilege “involves a substantial infringement on the rights of accused persons and carries with it a grave risk of miscarriages of justice”.

Hatzistergos, who is now chief commissioner of the Independent Commission Against Corruption, expanded the scope of the privilege in 2010 and told parliament it was designed to limit disclosure of protected confidences at the earliest possible point.

“The privilege is not just designed to prevent the unnecessary adduction (or presentation) of evidence of protected confidences before a jury, but is designed to prevent the inappropriate subpoena of such confidences in the first place, and then the inappropriate granting of access to them,” Hatzistergos told parliament.

There is one more issue. In support of its campaign, news.com.au cited the appalling treatment of Diane Lucas, administrator of the Canberra Rape Crisis Centre, who was jailed for refusing to hand over a rape survivor’s counselling notes when served with a subpoena.

But this predates Shaw’s 1997 legislation.

Robyn Gilbert, a senior solicitor with Legal Aid’s Sexual Assault Communications Privilege Service, outlined the Lucas prosecution for the NSW Judicial Officers’ Bulletin in February last year.

She wrote that after Lucas’s jailing in 1995, “calls for reform followed and in 1997 the (NSW) parliament created the sexual assault communications privilege”.

This history is important. Our criminal justice system has rightly addressed an imbalance that previously existed, where sexual assault survivors often faced aggressive cross-examination and significant barriers to conviction.

Now, we have a careful balance between the rights of accuser and defendant. Only by maintaining this equilibrium can we ensure our system is fair.