Over the past five years, proposals to introduce drug testing for welfare recipients have proliferated across the globe. In England, it was included in the Welfare Reform Act 2009 (yet never implemented) and in 2013, the New Zealand government introduced legislation which requires claimants to take pre-employment drug tests when requested by a prospective employer or training provider. Similarly, in over 20 US states there have been attempts to initiate drug testing of welfare recipients as a condition of eligibility for welfare, although frequently these controversial plans have either stalled or once introduced they have been halted through legal challenge.This article examines the process of introducing drug testing of welfare claimants in the UK as part of a broader strategy to address worklessness among problem drug users. Using Hudson and Lowe's (2004) multi-level analytic framework, which disputes ‘top down’ rational models of policy-making, it explores the mechanisms used for challenging drug testing policies. In so doing, it identifies the key policy actors involved, noting the alliances forged and strategies adopted to persuade the government to pursue alternative policies. Whilst the primary focus of the article is on the UK, consideration of the US and New Zealand facilitates comparison of the types of policy networks which emerge to oppose similar policies proposed in different socio-political contexts, and the forms of argument and/or evidence they inject into policy discussions. It is argued that a heavy reliance on rights-based arguments was a feature of opposing drug testing in the UK, US and New Zealand, and these featured more heavily than attempts to refute evidence underpinning these policies. However, there were important differences between jurisdictions in relation to the mechanisms used to challenge drug testing policies. These do not simply reflect the nature of the policies proposed but instead are reflective of different modes of governance, which influence the character of the policy networks formed and their judgements about the most effective ways of opposing what they regard as essentially flawed policies.