The government introduced its Misuse of Drugs (Classification of BZP) Amendment Bill to the House yesterday, and also introduced something else: a rare declaration from the Attorney-General that the bill is inconsistent with the Bill of Rights Act [PDF]. The reason? That the bill defines a limit beyond which posession is presumed to be for the purposes of supply, and imposes a reverse onus of proof on the defendant in relation to this. According to a recent Supreme Court ruling (R v Hansen [2007] SC 7 [PDF]), this violates the right affirmed in s25(c) to be presumed innocent until proven guilty. This inconsistency is so great (and the right violated so important) that it can not be considered a justifiable limitation (though it is suggested that it might be if the limit was much higher).
As mentioned above, this isn't just a problem with the BZP bill, but with the Misuse of Drugs Act as a whole. The Law Commission is apparently taking a look at the Act, which will hopefully fix this problem in the long term.
Meanwhile, I can't help but wonder where the Attorney-General's concern for the right to be presumed innocent until proven guilty beyond a reasonable doubt was when the government introduced this atrocity...