Doctors who help patients take their own lives via telehealth, phone or email could be charged with a criminal offence after a court ruled the practice equated to suicide.

An application before the Federal Court sought to clarify whether doctors who assisted patients under Victoria's voluntary assisted dying laws using a carriage service would fall foul of the law - with the decision having national repercussions.

Victorian GP and Dying with Dignity board member Nicholas Carr asked the court to rule on the "grey area" once and for all.

"I was seeking absolute clarification. We needed to know for sure. Either the commonwealth provision did cover (voluntary assisted dying) laws, or it did not," he told AAP on Thursday.

In his submission, Dr Carr said the criminal law was there to prevent harm to vulnerable people from being pressured, but the assisted dying laws recognised the person's own intentions to take their own life.

He argued the terms "committing suicide" and "assisted dying" were two separate forms of death and should not be construed as meaning the same thing.

Dr Carr also argued the federal law would undermine state legislation.

The federal attorney-general, who was the respondent to the Federal Court application, contended that when the criminal code was introduced in 2005 "commit suicide" referred to the intentional taking of one's life, regardless of the circumstances in which that occurred.

Federal Court Justice Wendy Abraham ruled on the side of the Commonwealth, stating the definition of assisted dying was consistent with suicide under criminal law in that it is "the intentional taking of one's own life, and the act of doing so".

"That is based on the ordinary meaning of 'suicide'; as it was in 2005 and remains today," she said.

"Assisting a person to commit suicide via a carriage service, regardless of the circumstances, was an offence."

Doctors will still be permitted to provide voluntary assisted dying to patients who meet the criteria under in-person consultations.

An extremely disappointed Dr Carr characterised the decision as not about human beings and medical care but dictionary definitions and use of language.

He feared the judgment could disadvantage people who were very sick and at the end of their lives, particularly in regional and rural areas of Australia.

"I'd be very worried that there will be people in more isolated parts of Australia who say I can't make that journey, I have to do it my way."

A spokeswoman for federal Attorney-General Mark Dreyfus said he was aware of the judgment and submissions concerning interpretation of the criminal code were made on his behalf.

"The government will consider the court's judgment," she said.

A Victorian government spokesman described the ruling as "incredibly disappointing" especially for regional residents.

Queensland Health Minister Shannon Fentiman accused the Commonwealth of "standing in the way of Queenslander's getting access to voluntary assisted dying via telehealth".

Both jurisdictions called on the federal government to amend the criminal code to allow all Australians to have access to voluntary assisted dying by phone or teleconference.

Go Gentle Australia chief executive Linda Swan described the ruling as a "retrograde decision" that reflected an Australian society of decades ago.

Victoria was the first state in the country to introduce voluntary assisted dying laws, passing parliament in 2017 and taking effect in 2019.

On Tuesday, NSW became the final state to enact voluntary assisted dying laws.

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