The article attempts to answer whether, and if so, to what extent, the withdrawal of the United Kingdom of Great Britain and Northern Ireland from the European Union (the so-called Brexit) impacted the British model of democracy. The starting point for the analysis is the famous classification of Arend Lijphart, who distinguished two main models of democracy – Westminster and consensus – identifying the United Kingdom as a prime example of the first of them. Using the method of institutional and legal analysis and the historical method, the author tries to prove the thesis that Brexit has shaken the foundations of the majoritarian democracy in the United Kingdom. However, the transformations of this model are not a new phenomenon, as they are part of the trend of changes occurring in this country, at least since the end of the 1990s. The article also proves the thesis that the serious political and systemic tensions to which Brexit – for very different reasons – led can be treated as temporary, as there is little indication that these tensions would permanently undermine the foundations of the Westminster model of democracy in the United Kingdom.