The Canberra Liberals would reverse the ACT government's controversial new cannabis laws if they win the next territory election.
Shadow attorney-general Jeremy Hanson said the laws, which come into effect from January, would encourage an increase in cannabis use in the ACT.
"We would rescind the laws, it's bad laws," Mr Hanson told ABC radio on Wednesday morning.
"We [previously] had a good regime that was working effectively. It provided a good balance for deterrence, particularly for young people, for cannabis use."
The new laws would allow for an individual to carry up to 50 grams of cannabis and grow up to two plants at their home.
Federal Health Minister Greg Hunt called on the ACT government to provide medical evidence that supported the territory's new laws.
The federal government has not ruled out overturning the AC'T's laws. Many ministers attacked the legislation after it passed the Legislative Assembly last month.
Mr Hanson said the laws would condone cannabis use in Canberra, with ambiguities about whether Canberra residents would be charged under federal law.
"It puts the police in a difficult decision," he said.
"The reality is there's an inconsistency that needs to be resolved.
"It's very problematic for people that are consuming cannabis and they think they are doing something legal but it's illegal under federal law."
Those charged with cannabis possession under federal law can face a maximum of two years in jail.
ACT Attorney-General Gordon Ramsay told his federal counterpart that any move by the Commonwealth to intervene in the laws would be deeply concerning.
Writing to Federal Attorney-General Christian Porter on Monday, Mr Ramsay said the laws were "the will of the people".
"I ... convey my deep concern should the Commonwealth seek in any way to overrule and intervene in the democratic processes of the ACT," Mr Ramsay said.
Mr Hanson told ABC radio he had had conversations with the federal government over the cannabis laws.
While Mr Hanson said he would look to repeal the cannabis laws, he would be concerned if the federal government tried to overturn the ACT government's decision.
"I can understand the motivation [to rescind the laws] from a policy point of view, but I'm equally conflicted because I'm very strong on territory rights," Mr Hanson said.
"I disagree with what the ACT government's doing, but I don't like it when the federal government overrules ACT legislation."