This article traces the emergence and development of claims that the 2016 referendum on the UK's membership of the European Union delivered a mandate for a so-called 'no deal' Brexit. Utilising Lacanian ideas about group mobilisation combined with a detailed content analysis and evidence drawn from polling data, it shows that this no deal narrative should be viewed as a discursive project that was constructed by a section of Leave campaigners relatively late into the Brexit process amidst growing disillusionment with the direction that negotiations with the EU were taking. By emphasising the role of Brexit as an 'empty signifier' the article shows that Brexit was initially successful in mobilising and uniting a disparate, but often unconnected, range of discontent to its cause. However, over time the complexities of the Brexit process triggered a discursive 'war of position' as competing visions of Brexit attempted to vie for dominance amongst the Leave camp. It is within this context that the myth of no deal emerged as an attempt by an elite group of actors to re-mobilise support for their cause.