Medicinal cannabis could be legally grown and prescribed to patients as early as next year under a cross party bill that has attracted initial support from Prime Minister Malcolm Turnbull.

Greens leader, senator Richard Di Natale, announced on Monday that the bill to create a regulator for medicinal cannabis for certain conditions had been drafted and would be put before the Senate for a vote in November.

While Victoria and NSW state governments had indicated that they wanted to legalise medicinal cannabis, a federal regulatory scheme was required to do this: "We need national laws to make sure we can licence growers … that doctors can prescribe this and that the medication gets in the hands of patients who need it."

If passed, there was "no reason" Australia could not begin importing medicinal cannabis and make it available for patients next year, ahead of creating a locally grown industry for the drug.