This dataset comprises a set of online footprints extracted from Twitter using the available APIs. It is centered around the Brexit debate on Twitter from the 2nd until the 21st of June 2016. Data consist of (i) a social graph where nodes are users and an edge (u,v) represents that user u follows user v, (ii) a set of tweets enriched with a polarity label (-1 if the tweet supports the Brexit, +1 it is against Brexit) and the retweet chain (the set of users in the social graph who retweeted it), and (iii) the political stance of a subset of users in the social graph manually annotated by the two authors (whether the user is supporting or contrasting the Brexit). We started from a public dataset1 consisting of a social graph of users active in the online Brexit debate, and we further enriched it with other information listed before. This dataset can serve scholars interested in Social Network Analysis or Information Diffusion on Networks.