Navigating hope and deterrence: the ambivalence of legal support in post-Brexit Calais

European border regimes increasingly deploy a politics of deterrence that seeks to discourage specific people from crossing certain borders. Given the pivotal role laws play within this politics of deterrence, there have been surprisingly few in-depth accounts of the informal practices of providing legal support to people on the move. In this article, we draw on ethnographic work conducted in post-Brexit Calais to explore how legal support actors tactically navigate this hostile environment. We analyse how the structural informality of European border regimes exacerbates the ambivalence of the law, forcing legal support actors to constantly assess whether their actions amplify or counter a politics of deterrence. We show how, despite being unable to fully resolve this ambivalence, they actively deal with it by balancing transparency and care, by leveraging legal uncertainty, and by exposing the performative nature of migration law. By doing so, they seek to harness hope against an increasingly violent politics of deterrence.