The paper focuses on media image construal of the Slavs against the backdrop of Brexit procedure. The objective of the author is to examine cognitive-discursive mechanisms of representing the Slavic national groups (Western, Eastern, Southern) in the British media, in the context of Britain’s withdrawal. Cognitive-discursive analysis, integrating advances of European and Russian linguistics, is employed. The term ‘discourse-world of Brexit’ is considered to be a conceptually complex discourse-level structure, serving as a background, against which national images stand out. It is argued that images of the Slavs are organized by frames, which enable media managers to negatively or neutrally evaluate members and non-members of the European Union. Media frames, structuring the national images, are systematized. Examples from the News on the Web corpus are used to prove that images of the Slavs are discursively constrained and biased. The results might present interest for further investigation of prejudices in the media.