The European Union's security depends on how stable and peaceful its neighbours are, and yet the security situation around it has been deteriorating in recent years. The EU policies designed to stabilise the neighbourhood - the European Neighbourhood Policy (ENP) and EU enlargement - were originally designed as "low politics" of foreign policy focusing on economic instruments and tools of democratisation, but in time security became a prime concern. The article firstly shows how the European Parliament and national parliaments narrate these challenges in the neighbourhood and how security-related concerns become central to the ENP and enlargement. Secondly, in capturing the security concerns, it also shows how such changes contribute to the politicisation of relations with neighbours and how these processes differ between national and supranational level. Empirically, the politicisation of the ENP and EU enlargement in national parliaments (the UK, Poland and Ireland) and the European Parliament between 2004 and 2014 is compared and analysed.