While European integration had always been contested at the elite level in Britain, the Brexit referendum turned it into a hyper-politicized issue at the heart of British political debates more generally. Despite the growing literature on Brexit, however, there has been little substantive research on how EU integration has been politicized outside the electoral arena, namely in citizen campaigns and street protests across the UK. This is all the more important since in the aftermath of the referendum the vertical sovereignty conflict between the EU and the UK catalyzed another type of horizontal conflict between different visions about who is sovereign in the UK – the “People”, the Parliament, or the Government. This paper aims to answer how “the People” themselves - protesters, campaigners, and petition organizers – understood sovereignty in Brexit debates and mobilized around it. Drawing on a Discourse-Network Analysis of media articles on Brexit-related mobilizations, I show that both pro-Remain and pro-Leave citizens shared the same frames – popular and parliamentary sovereignty. Yet, they were deeply divided on what follows from the claim that “people are sovereign” - honouring the Brexit result or a second People’s vote? Similarly, the claim that “parliament is sovereign” meant for Leavers above all independence from EU influence, while for Remainers it meant that parliament could control and scrutinize the UK government itself. Thus, rather than a unitary “British people” with a single “will” to be honoured, what could be observed was a “people” divided on key issues. Furthermore, I show there was no such thing as “pure” popular mobilizations in the UK protest arena – all key events had as speakers or organizers figures from party politics. Ultimately, my analysis reveals that debates on EU membership gave rise to a deeper conflict traversing all political arenas in the UK on how to interpret and, crucially, act on key frames such as popular or parliamentary sovereignty.
