The Attorney-General has raised concerns about aspects of a Government bill seeking to change the law on drugs.
The Misuse of Drugs Amendment Bill would reclassify pseudoephedrine and ephedrine as Class B2 drugs, but Chris Finlayson says part of the legislation breaches the Bill of Rights Act.
The aim of the reclassification is to make it more difficult for potential manufacturers of methamphetamine, or P, to get hold of the key ingredients.
But Mr Finlayson says the bill changes the onus of proof by requiring a defendant found with the drugs to prove they do not intend to use them for supply, which is inconsistent with the Bill of Rights.