Attorney-General Gordon Ramsay has told his federal counterpart any move to intervene in the "democratic processes" of the ACT to try to overturn cannabis legalisation laws would be of deep concern.
It comes as Chief Minister Andrew Barr penned a response to federal Health Minister Greg Hunt's call for medical "evidence" that supported the ACT's move to legalise cannabis.
It's the latest development in a battle brewing between the federal and ACT government about the laws - which would allow adults to possess up to 50 grams of cannabis and grow two plants - that passed earlier this month.
While the federal government stayed relatively quiet in the year between when the bill was introduced and passed, Coalition ministers came out in attack after the laws were passed, calling them "crazy".
It has not ruled out seeking to overturn the laws.
Mr Ramsay wrote to the Federal Attorney-General Christian Porter on Monday, providing him a final copy of the legislation.
"I reiterate my previous advice that this legislation expresses the will of the ACT people and convey my deep concern should the Commonwealth seek in any way to overrule and intervene in the democratic processes of the ACT," he said.
Mr Ramsay said he trusted the time and resources of federal police and courts would not be wasted pursuing individual cannabis users - as is open to them under Commonwealth law.
It came after Mr Hunt wrote to Mr Barr last week, asking him to provide evidence that disputed adverse health effects linked to cannabis use.
"I have serious concerns the ACT's legislation will result in further health harms and exacerbate mental health issues, particularly for those who have a family history of mental health disorders." he said in the letter.
"I note that both the Australian Medical Association and the Royal Australian College of Surgeons have also expressed concerns over the legislation, with the latter calling for it to be reversed.
"The evidence base regarding adverse health effects linked to cannabis use has broadened considerably since the gradual decriminalisation or legalisation in certain countries."
Mr Barr on Monday replied to the letter, saying the government did not dispute that cannabis could have adverse health effects, but that harm minimisation principles had informed the reform.
"It is the government's view however that the outright prohibition of cannabis is of limited, and often negative, effect when seeking to reduce the harms caused by cannabis use," Mr Barr said.
"The health risks you have outlined, and which the government is aware of, already exist for the 9.4 per cent of Canberrans that have reported using cannabis in the previous 12 months."