This dataset contains the replication files for the article: Nuria Font (2020), Competing Principals and Non-Vote Decisions in the European Parliament. Parliamentary Affairs, which analyses the effects of competing principals on legislators' decisions not to vote in the European Parliament. We argue that Members of the European Parliament (MEPs) are likely to decide not to vote to avoid defecting from either the national party or the European political group when both political principals disagree. Moreover, the article demonstrates that competing demands between principals interact with the expected closeness of a vote. MEPs are more likely to opt for not voting when they have few chances to influence the vote outcome and are torn between the two main principals. Based on a novel data set on individual votes in the 2009-2014 term, this article demonstrates that competing demands moderate the effect of the expected vote closeness on non-vote decisions and highlights the need to incorporate this type of legislative non-response in future research.