The United Nations has warned Canberra that legalising cannabis will breach international law.
In a letter to the Federal Government, the UNs' International Narcotics Control Board (INCB) reiterated that the legalisation and regulation of cannabis for non-medical use, including in small quantities, were inconsistent with international drug conventions.
Australia, along with more than 200 other countries, signed three international conventions agreeing to certain rules about illicit drug use and restrictions about medications.
A member of the UN board, Professor Richard Mattick, who is also part of UNSW's National Drug and Alcohol Research Centre, said the treaties were legally binding and the ACT's cannabis laws were in contravention. He said that while the ACT was apparently only proposing to legalise a small quantity of cannabis per adult in Canberra, the amount was not relevant.
"The issue is the letter of the law," he said."Many countries do feel very strongly about this ... and the vast majority of the 200 countries that have signed the Drug Conventions, are not in agreement with this.
Federal Health Minister Greg Hunt, who has already sounded his opposition to the ACT's move, said it was clear that the legislation was in breach of the UN convention.
"The Australian Government remains committed to the international drug control regime established by the UN international drug conventions which do not support the legalisation of cannabis for recreational use," Mr Hunt said.
"While many Australians may view cannabis use as harmless, almost a quarter of Australia's drug and alcohol treatment services are being provided to people identifying cannabis as their principal drug of concern, roughly the same number of treatment episodes as for amphetamine use."
"Federal Government ministers sharply criticised the ACT's move, with some labelling it as "crazy" and a "social crusade" by the territory Labor government.
For its part, the ACT Government said the legislation was "the will of the people".
Drug Free Australia challenges that and wants to see the evidence for , given that the majority of Australians . 86% of Australians, according to the 2016 National Drug Strategy Household Survey, do not approve the regular use of cannabis, and two out of every three Australians do not want cannabis legalised.