On 25 May 2014 European citizens were called to vote to renew the European Parliament. In Belgium this day is ‘the mother of all elections’ since all legislative assemblies are renewed simultaneously. The 2014 Belgian general elections give the opportunity to study European parliamentary elections in a context of co-occurrence of elections. Starting from the assumption that EP elections are said to be ‘second-order’ elections, the paper empirically tests a hypothetical definition of a ‘second-order’ candidate selection process. By doing so, it attempts to bridge the existing gap in the literature between research on candidate selection and the ‘second-order’ elections model. 11 Belgian political parties are analysed thanks to a comprehensive comparative analysis of party statutes, in-depth interviews with key party figures as well as media analysis. The paper takes advantage of co-occurrence of both first- and second-order elections to launch the reflection on the conceptualisation of a second-order selection process.