The adoption by jurisdictions like Canada, Australia, the UK and New Zealand of relatively novel mechanisms for resolving disputes about rights has led to the development of several ostensibly novel models of constitutional adjudication.The most high profile of these - notably Mark Tushnet's distinction between weak and strong-form review, and Stephen Gardbaum's Commonwealth model of constitutionalism - place emphasis, in particular, on the provision of a legislative power to override a judicial determination. It is argued, especially by Gardbaum, that this vesting of the final say in the legislature avoids the weaknesses of both political and legal constitutionalism and so represents a better alternative to traditional theories of legislative or judicial supremacy.This paper argues that Gardbaum's claims are misconceived. Using examples from other jurisdictions, the paper suggests that the claimed novelty and hybridity of the model is based on a caricatured image of alternative approaches to constitutional adjudication. In particular, it is contended that the Commonwealth model's concentration on the idea of the 'final say' is misleading, illusory and gives rise to a false choice between extremes. The critical consideration in any system is not how the mechanisms are designed but how they actually operate.In reality, the contingent and disaggregated nature of modern government means that it is unlikely that any institution will have the 'final say', in the sense of commanding the complete and permanent implementation of its intentions.This, it is suggested, provides the basis for an alternative model of collaborative constitutionalism. This model proceeds from an acceptance of the contingent nature of institutional decision-making to suggest that institutions, like courts and legislatures, should therefore be regarded as engaged in the collaborative enterprise of constitutional governance. By freeing constitutional theory from the necessity to make a false choice between judicial or legislative supremacy, collaborative constitutionalism allows constitutional scholars to concentrate on more practically-important issues of institutional competence, respective expertise, protocols for inter-institutional engagement, and so on.