Abstract
The rules concerning the inconsistency of Commonwealth and territory laws have been little explored and largely neglected. They rose to recent prominence in the challenge to the validity of the ACT's same-sex marriage laws. The ACT claimed that even if the Commonwealth's Marriage Act was intended to cover the field, the ACT's same-sex marriage law could still operate concurrently with it, because of the different application of inconsistency rules in the ACT. This article considers how inconsistency rules operate in the different territories, what was intended by the ACT inconsistency provision, how the High Court determined the issue, and whether a better explanation can be given for the outcome.