This chapter considers how the environmental impact of human economic activity is construed and dealt with in European Union official and legal documents. This is done by focusing on how the EU construes corporate social responsibility. The hypothesis is that the concept has developed and that the regulator is now imposing the responsibility on companies more bindingly than before. Is regulatory control increasing? The paper first reviews how critical discourse studies techniques can be applied to studying the conceptual development in legal discourse and secondly, to discuss the persuasive strategies the EU employs in order to bring about this development. The analysis draws on the theoretical framework of critical discourse analysis pragmatics and speech act theory. A Green Paper, a White Paper and a Directive forming a continuum will be analysed more in detail. Findings show that the construing of sustainability and the stance towards CSR are evolving in European legislation on the scale from voluntary towards mandatory.