The ability of corporate social responsibility (CSR) to address environmental and social problems is not universally agreed, while the way in which we facilitate CSR and, moreover, continually improve its effectiveness is unclear. Central to the debate is the extent to which the role of law ought to interact with the promotion of CSR, and this in turn raises questions over the effectiveness of different regulatory frameworks. Ecological modernisation theory suggests that a shift away from government-mandated, direct regulation, towards market driven innovation (with the state acting in a steering capacity), can help to align the apparent incompatibility between social/environmental issues and economic growth. A key component of this discussion is the use of reflexive instruments, which enable firms to effectively self regulate, in varying degrees, in response to complex problems.The enactment of the Companies Act 2006, which introduced for the first time the mandatory requirement to report on various social and environmental issues, is one such example of reflexive law in practice and arguably represents a significant step forward for the CSR movement. Whilst its implications are potentially significant, there has been limited research to date into the extent of the changes made, if any, to the nature and quality of information provided by companies to stakeholders via corporate disclosure. This thesis contributes to the discussion by offering a comparative critique of corporate disclosure both pre and post the Companies Act 2006, in order to draw causal inferences resulting from the legislative changes. It is suggested, ultimately, that while appropriately framed reflexive mechanisms, such as mandatory reporting, can act as a powerful tool to induce behavioural change, this is likely to require a number of factors being realised. At present, it appears that there may still be a long way to go before we achieve the depth of change required to bring corporate behaviour in line with an ever-changing market.