The bill was introduced into Parliament last November and sent to a committee in February. After conducting public hearings around the country and attracting almost 200 public submissions, the committee is due to deliver its report on August 10.

Sources say the committee will back the bill despite strong concerns from the Health Department.

In its submission to the committee, the department said the bill would set up a new regulatory system that would create "complexity and uncertainty" and potentially clash with the Therapeutic Goods Act.

Department secretary Martin Bowles warned the bill left important legal and practical issues unidentified or unresolved, "leading to the risk of regulatory gap, overlapping laws and a lack of clarity about the exercise of jurisdiction by agencies and possible inconsistency with other existing laws".

The department also warns the bill could contravene some of Australia's international obligations under the Single Convention on Narcotic Drugs.