Social media platforms are becoming common sites for public debate on political events, and they are going to play an important role in shaping perspectives and behaviours. The Scottish independence referendum is an opportunity to observe and interpret the public debate in a unique set of political circumstances. Analysing data collected from Twitter, our research explores the network of communications between individual users, public figures and campaign groups who engage with this debate in the six months preceding the referendum. The aim of this research is to show how such a platform is used during a political campaign, and what are the dynamics and evolution of the referendum debate. The results of this research also provide useful insights into the role of social media in channelling new perspectives and reflecting, or impacting on the wider political discourse in society, and they point to new ways of doing public communication.