While euthanasia, or voluntary assisted dying, remains illegal in most Australian states, it's expected by mid-2021 all will have passed laws or introduced bills allowing for its legalisation.

However, the Australian Capital Territory and Northern Territory are legally prohibited from making that decision due to a federal law passed in 1997.

The two territory governments joined forces this week, writing a letter to the federal government to demand that legislation be adjusted.

Decades of political debates preceded the initial decision but the renewed push to change the laws could see the territories given back their own choice.

Euthanasia has never been legal in the ACT but an amendment introduced in the 1990s made the road to legalising it even more bumpy.

The difficulty began when the territory's northern sibling made strides forward.

In 1995, the Northern Territory passed a bill legalising euthanasia, becoming one of the first jurisdictions in the world to do so.

While Australia was now at forefront of the movement, the law's passing caused outrage in the country with a number of groups pushing the federal government to overturn it.

While the territories' populations have their own representatives, their legislative assemblies don't enjoy the same independence as the states do. Ultimately, they fall under the control of the federal government.

Because of this, former Victorian MP Kevin Andrews introduced an amendment in 1996 that would override the territories' ability to pass laws relating to legalising euthanasia.

By the following year, the Euthanasia Laws Act 1997 had passed through Parliament, denying either territory's assembly from legalising the controversial practice while the act remained in effect.

But a renewed push this week by both territories could mean the mounting pressure on the government might be enough overturn that amendment.

Victoria became the first Australian state to allow for euthanasia, which came into effect in 2019, while Western Australia expects it will become an option for residents by mid-year.

Support for the practice has grown considerably in other states and legislation is set to be drafted and introduced in New South Wales this year.

Queensland, South Australia and Tasmania all have plans in motion to legalise voluntary assisted dying, too, with the latter needing to clear a final hurdle before legislation this month.

Tasmania Premier Peter Gutwein said in December he hoped the laws, once amended and passed, would make it a reality in his state by mid-2022.

ACT Human Rights Minister Tara Cheyne and NT Attorney-General Selena Uibo this week wrote a joint letter to the federal Attorney-General Christian Porter to rectify the act, claiming it was a breach of international laws.

By the end of the year, the letter said the territories would remain the only jurisdictions in Australia yet to legalise the right to a voluntary assisted death.

"This starkly demonstrates the inequitable position of the ACT and the NT," the letter read.

"That this situation continues to persist is not only untenable, but it is inconsistent with Australia's international human rights obligations."

READ MORE:

Ms Cheyne and Ms Uibo wrote the 1997 amendment was a potential violation of International Covenant on Civil and Political Rights, which provides people with the right to to take part in the conduct of public affairs through freely chosen representatives.

"By prohibiting the citizens of the ACT and the NT from deciding for themselves, through their elected representatives, whether to legislate in the areas of voluntary assisted dying, the legislative restrictions placed on the NT and ACT ... may limit this right," the joint letter read.

While the proposed changes have bipartisan support in the NT, they don't have the complete backing of both the parties in the capital territory.

Canberra Liberals leader Elizabeth Lee has remained silent on whether the territory's party branch would also support the push but has previously said she personally supports it.

With the Andrews Bill remaining as legislation, the territories will not be able to introduce or legislate euthanasia. But the solution is relatively simple, some believe.

Labor member for Fenner Andrew Leigh told The Canberra Times on Thursday all it would take was a simple adjustment in Parliament.

"You look back to 1997 and both the ACT and the NT were relatively young jurisdictions. That is certainly no longer true," Mr Leigh said.

"The world has moved on, but the Andrews Bill hasn't. I think it's important to just keep up the pressure so that the NT and the ACT have the same powers that the states have.

"It could be done very quickly if the Morrison government would only let the issue be debated in Parliament."

Mr Leigh added he would introduce a motion calling on the government to overturn the decades-old exemption.

If overturned, the territory governments would then have the power to introduce their own bills and pave the way for legislation.