In 2004, the U.K. parliament passed the Civil Partnership Act which provides a scheme to enable same-sex couples to obtain formal recognition of their relationships through the registration of a civil partnership. When the Civil Partnership Bill was making its way through parliament, attempts were made in the House of Lords to derail the Bill through amendments seeking to extend the Bill to certain familial relationships of care and support. In order to counter these attempts and to facilitate the removal (...) of the amendments, the government gave the assurance that the matter of the economically vulnerable cohabitant would be referred back to the Law Commission for England and Wales for review. Consequently, in July 2005, the Law Commission commenced its project on cohabitation. This paper seeks to examine models of reform (such as the one proposed by the Law Society of England and Wales in its 2002 Cohabitation report) as well as those introduced in other Commonwealth countries. The aim is to identify some of the crucial questions that the Law Commission will need to give careful consideration to if they are to make recommendations that will provide a more radical approach to this area of the law, rather than adopt the more conservative approach of including cohabitation in ‘piggy back’ mode on the marriage model. (shrink)