Abstract: The article aims at contributing to discussions on British national identity and its impact on the state’s foreign policy, with British-European relations used as an example. The author provides a concept of “fear” within the constructivist approach as a tool to explain withdrawing from the integration organisation. According to it, the logic of state’s behaviour can be explained with the help of four impulses that cause fear for one’s own identity. These are generalised categories that make it easier to analyse and describe actions taken by actors while interacting with their counteragents. Given the results of the research on British-European relations, one can conclude that deeper integration and gradually empowered supranational bodies provoke conflict between national and transnational identities. For fear of being deprived of its identity, which is of paramount importance, the United Kingdom was trying to securitise the threat by leaving the Union. Accordingly, the concept of “fear” facilitates defining reasons why politicians turn to politicising a problem and developing a security scenario, which is Brexit when it comes to British-European relations. Yet, it doesn’t guarantee identity restoration and can only aggravate internal issues, which is proved by the case of Great Britain.