Australian Taxation Office (ATO) whistleblower Richard Boyle has told a South Australian court he plans to testify in his own defence when he stands trial next year.

Mr Boyle, a former ATO debt collection officer, first became an internal whistleblower in October 2017, when he grew concerned about operations in the tax office.

When his complaints were ignored, he went public and told Four Corners about the culture at the ATO, which he said included his area being instructed to use more heavy-handed tactics on taxpayers who owed the tax office money.

Mr Boyle is accused of 24 offences, including taping private conversations without consent and taking photos of taxpayer information.

The charges carry a maximum prison sentence of up to 46 years.

His lawyers had been desperately trying to invoke whistleblower protections to help him avoid a criminal trial.

However, last week Mr Boyle lost his last chance to secure immunity from prosecution when the High Court refused his application for special leave to appeal, after two South Australian courts previously rejected his bid.

Mr Boyle has appeared in the District Court and Judge Liesl Kudelka set a date for the trial to start in November next year.

During the hearing, Mr Boyle told the court "I intend to take the stand" at trial.

Judge Kudelka listed the trial period for three weeks, but said she did not believe it would take that long "knowing the issues".

"I want counsel from both sides ready to address me on that in December."

Speaking outside court, Mr Boyle said it was "incredible" and "really heartening" to be greeted by dozens of supporters as he left the hearing.

He said the current legislation designed to protect whistleblowers was "broken" and called for a "complete overhaul" by the government.

"I was extremely disappointed that my High Court appeal special leave application was refused, that means that there is no impediment to my prosecution," My Boyle said.

"Our Attorney-General, Mark Dreyfus, said recently at a speech that he was extremely proud of his public interest disclosure laws that he introduced … and that he was also incredibly proud of his amendments to the whistleblower protections, strengthening those protections.

"I don't know what rational person can be proud of a law that is supposed to protect whistleblowers when the only person who has ever sought immunity under the Public Interest Disclosure Act is myself.