Drawing on models of expertise, developed by policy scholars this paper examines how values, and politics enter highly contested policy debates and into legal decision-making by government agencies. I will explore the findings of a case study on the controversial Australian airspace reform “NAS2b” to highlight how lawyers advising different actors within that debate, positioned their advice on the legal process and integrated their advice with non-legal considerations in the policy mix. The paper concludes with a discussion about how insights from this study might help lawyers position themselves in solving future policy problems. This paper seeks to fill a gap between the treatment of the role of lawyers in literature concerning government lawyers, and public policy literature around the role of experts in policy. Specifically, this paper will add to the small number of empirical studies into how government lawyers and decision-makers experience their role in practice.