Policymakers across Europe are once again proposing to enhance punitive measures against asylum seekers as a strategy to deter prospective migrants from attempting to reach their respective countries. This paper examines the following question: Are restrictive immigration policies effective in reducing irregular and asylum-seeking immigration? Adopting a process-tracing approach, the study investigates the case of the United Kingdom, analysing whether migrants are aware of asylum policies before arriving and whether such awareness influences their decision to migrate to the UK.The UK serves as an 'extreme case' of deterrence-oriented immigration policies. At the time of fieldwork in 2024, the Conservative government had enacted legislation that effectively constituted a 'ban on asylum' and was preparing to relocate asylum seekers to Rwanda.

Drawing on 50 interviews conducted with migrants residing in Calais and intending to reach the UK, the analysis reveals a disparity in migrants’ knowledge of British asylum policies. While they are generally well-informed about access control policies (that govern entry and removal) like the Rwanda plan, they are poorly informed about determination process (that determine how asylum claims are processed) and integration policies (that regulate their access to rights). This suggests that implementing restrictive determination process and integration policies with the aim of curbing immigration is inefficient. Restrictive policies cannot deter people who are unaware of their existence. Overall, these findings challenge the dominant rationale underpinning the implementation of restrictive immigration policies to deter unwanted immigration.