The birth of a ‘tacit’ constitutional convention: The Collaborative Constitution and the effect of a declaration of incompatibility

This book review article considers some of the core themes discussed in Aileen Kavanagh’s The Collaborative Constitution, in particular its exploration of the concept of the separation of powers as it actually functions in the United Kingdom (UK). The first section addresses Kavanagh’s well-received recent contribution to the long-running debate over ‘constitutional dialogue’. The second section directly focuses on the ‘nascent’ convention that Kavanagh suggests has emerged in the UK and the evidence she offers for this suggestion. Kavanagh details the multiple mechanisms by which institutions collaborate to protect rights. The final section examines the decision by Kavanagh to label the purported convention she identifies as merely ‘nascent’. The argument presented here is no less careful than Kavanagh herself to avoid any crude lapse into simply trading blows on who has the ‘last word’. Instead, it considers whether we are witnessing the birth of a ‘tacit’ constitutional convention.v