AbstractCollaboration is ubiquitous in public policy life, with its presence and profile determined by prevailing governance conditions. Commitments to globalisation and marketisation in the latter part of the 20th century marked the onset of an era defined by collaboration, between and across tiers and spheres of government, with non‐state actors, and through market and network instruments. Current contextual instability poses questions for dominant public policy paradigms and the existing collaborative settlement. This article explores the challenges presented in the current moment and how policymakers and scholars might navigate them. It focuses on how ideas about economics and security shape public policy, illustrating the paradigm‐shifting impact of economism and securitisation. It argues for the replacement of economism and securitisation by sustainability, sovereignty, and justice and demonstrates the latter's engagement with economics and security and their accounting for what have hitherto been ‘subaltern voices’ in public policy. It discusses the implications for collaboration in relation to future collective action problems, more diverse and disconnected ‘publics’, and a more congested and lower trust policy environment. It highlights the need for collaborative plasticity and pluralistic agency.Points for practitioners Public policymaking is shaped by dominant ideas about economics and security; ideas that become ‘taken for granted’ in policy practice. The prevailing ideas of economism and securitisation are being challenged by contextual changes, globally, regionally, and nationally. This creates space for new ideas to shape future public policy. Ideas of sustainability, sovereignty, and justice offer an alternative framework for public policymaking. These ideas can engage productively with economics and security, and they are also inclusive of a wider variety of ‘voices’ particularly those previously marginalised. Collaboration will remain integral to the success of public policy. However, it will need to adapt to new circumstances. This will include defining new purposes, reassessing its appropriateness, reshaping collaborative scope, scale, and form, and refining collaborative activities. A paradigmatic shift in public policy that highlights sustainability, sovereignty, and justice will require the active involvement of a plurality of actors enabled to contribute new knowledge and contest the status quo.