Public debates leading to the 2016 Brexit vote largely drew on the presumed link between membership to the European Union, uncontrolled borders, and unwanted immigration. Drawing on British government archives and interviews with senior Home Office officials, this dissertation examines British immigration policy during the first two decades of membership to the European Communities (later, Union) to understand the impact of membership on domestic policymaking. Drawing on French government archives and private papers, it also seeks to understand whether European integration, and the slew of semi-formal, multilateral meetings that accompanied it, contributed to harsher immigration policies, as the securitisation literature would suggest.

My key findings are that (i) British immigration policies were formed and implemented independently of European interference; (ii) the key dilemmas confronting British immigration policymakers were the result of globalisation, not European membership; (iii) European cooperation in immigration, security, and border issues emerged organically as states realised they faced similar structural problems, which a measure of coordination could help solve; (iv) a key driver of change was administrative overheating; (v) the importance and agency of ‘security professionals’ in bringing about more repressive immigration policies has been overstated in the political science literature.