On the surface, legalising marijuana in Canberra seems a fairly simple proposition. But if ACT Labor thinks its bill is going to float through the Legislative Assembly, it is mistaken.

Possession of small amounts of the drug is already decriminalised in the ACT and punishable by a $100 fine, but, since the idea of legalising cannabis was mooted, more questions have been raised than answers.

One major concern is the interaction between the proposed new laws and existing Commonwealth laws, which contain offences for possession of a prescribed drug.

Commonwealth laws tend to override territory legislation and there's little evidence (at least that's been publicly released) that this case would be any different.

Not to mention that if cannabis was legal in the ACT, users would still have to illegally acquire the seeds to grow their plants on the black market.

Those concerns prompted an inquiry — but the final report appears to cloud the air even further.

'Social houses' of up to 40 plants could be a possibility

ACT Policing said this photo showed how, using wires to support them, just two cannabis plants could be used to grow commercial quantities of the drug. ( Supplied )

In several areas, the Assembly inquiry recommended beefing up the legislation.

It wants a limit of four plants per person, not two, and hydroponic or artificial cultivation — mainly because it's hard to grow a tropical plant in a city that frequently braves sub-zero temperatures.

It also wants groups to be able to cultivate weed together, in "cannabis social houses".

That could mean up to 10 people growing 40 plants at one premises (if the recommendation of a four plant limit was accepted).

The only conditions; that cannabis isn't traded with outsiders and the names and addresses of those individuals be provided to police on request.

The inquiry argued social growing was meant to tackle inequities in a legal market — with some people not wanting to, or not being able to, grow their own plants.

But a hydroponic setup of 40 plants could easily be viewed as a grow house and could pose significant issues for police trying to crack down on big dealers.

Should the Government step in to defend smokers in court?

An inquiry into legalising cannabis was held to address growing concerns. ( ABC News: Meghna Bali )

While recommending that the bill should be passed, the inquiry attempted to address a number of concerns.

Its solution to the issue of overarching Commonwealth laws was to have the ACT Government intervene in any Commonwealth criminal prosecution.

The latter has already raised eyebrows and will no doubt prompt confusion within the police force.

ACT Attorney-General Gordon Ramsay said if the Government agreed to that recommendation, it could make submissions to the court in defence of the ACT laws.

Even then, it would require a person who believed they weren't doing something illegal to be charged first.

But the inquiry was less forthcoming on a solution to the issue of cannabis users breaking the law in order to legally grow cannabis.

"The Committee believes that the illegal provision of cannabis seeds to legally grow cannabis is in direct conflict with the bill's purpose," it said.

"However, given that provision of seed by one person to another person would be legally supply under Commonwealth law, the committee does not know how to resolve this issue."

Adding to the confusion for police and prosecutors, the inquiry also wants measures to overturn cannabis convictions, although it's unclear whether this refers to any convictions going forward or historical ones.

If it's the latter, the reasons for doing so — and consideration of how mammoth that task might be — are largely missing from the report.

And, in dealing with what legalisation could mean for drivers, the committee wants police to adopt a new scheme for drug testing actual level of impairment, like with drink driving.

But the police union has questioned whether that kind of technology even exists.

Dangerous report, dangerous bill

The inquiry recommended a limit of four plants per person. ( Pixabay: StayRegular )

The Greens have long been champions of legalising cannabis, and committee member and MLA Caroline Le Couteur is a noble warrior — having spent a significant chunk of time living in the pot haven of Nimbin.

But, despite endorsing all the recommendations, even she was not convinced about the legislation.

She admitted she didn't know how ACT Government intervention in Commonwealth laws would work and said the bill would be difficult to vote for if the Government didn't provide more clarity.

As a conservative, dissenting committee member and Liberal MLA Vicki Dunne was much more damning, describing the inquiry as irresponsible.

She believes the report is as dangerous as the bill.

Would the Commonwealth cooperate?

In the ACT, people can be either fined or sentenced to two years' prison for possessing up to 50g of cannabis. ( Flickr: Heath Alseike )

The committee argues legalising cannabis would take a large burden off the legal system, remove stigma and allow addiction and use to be treated like a health issue.

For the Government's part, it argues it will consider the recommendations before responding, but believes the Canberra community wants this done.

Mr Ramsay said he would negotiate with the Commonwealth to get some compromise on the legislation.

But recent history would indicate his view is optimistic.

Canberrans will remember the territory's attempt to legalise same-sex marriage being overturned.

More recently, Federal Parliament knocked back a chance for the ACT to regain its right to legalise euthanasia if it wanted.

But most relevantly, the Federal Government last year intervened to prevent ACT-Government-approved pill testing at a music festival on Commonwealth land in Canberra.

It's hard to see why the Commonwealth Government would want to cooperate on drug policy now.

And, with so many unanswered questions after the report, the inquiry may have done more damage to the cause than good.