On paper, the United Kingdom (UK) has the architecture in place to actually start delivering sustainable development. The current UK-wide framework for sustainable development and the individual strategies made under it are all relatively modern and progressive in considering environmental limits and long-term effects. This framework, however, lacks a legislative foundation in the UK. Moreover, these strategies are not delivering in the three areas considered vital for the proper implementation of sustainable development—improving understanding, providing a comprehensive framework to integrate potentially conflicting priorities and providing an operational toolkit. This article argues that over and above its symbolic and educational value, specific legislation setting out the state’s approach to sustainable development should impose mandatory obligations on policy and decision makers, with meaningful consequences both inside and outside the courtroom. Using examples from Wales, Canada and Scotland, it explores three legislative models to support the implementation of sustainable development that would be suitable in the UK and its devolved administrations, and the legislative provisions necessary for their delivery. This article emphasises the benefits of procedural obligations, both by themselves and in support of more substantive obligations, along with the possibility that certain appropriately worded substantive duties be treated as legal rules that govern decision-making. It explores the benefits and drawbacks of including a definition of ‘sustainable development’ and of referring to specific underlying principles such as the precautionary principle, concluding that these elements may not be necessary or suitable in the UK. The article also contends that sustainable development ought to be the central organising principle of government in the UK, and that even if a weaker and less ambitious formulation is adopted, legislative backing for the production, use and review of sustainability strategies would still improve understanding, provide a framework for decision-making and clarify the use and importance of other implementation devices.