Cannabis referendum could be untidy

One News reports:

While the specifics are not yet known, 1 NEWS understands the referendum will be broadly in-line with what the Green Party campaigned on at the 2017 election.
It campaigned on legalising possession and cultivation, or growing of plants, for personal use of cannabis and introducing a legal age limit for personal use.

If this is what is proposed in the referendum, that is untidy. It is saying it is legal to possess cannabis but presumably still illegal to buy it or sell it. It won’t get rid of the black market, but make it worse.

It is also understood the Government will not pass legislation before the referendum – but will instead prepare a Bill that could be introduced to Parliament afterwards if people do vote to legalise marijuana.  

Also unhelpful as if the bill has gone through select committee process etc, it will be more likely to be acceptable.

I’m in favour of legalisation, but am worried the referendum could end up being a no vote, because not enough thought has gone into how legalisation would work.