EU issue voting in European Parliament elections has been shown to be highly conditional upon levels of EU politicization. The present study analyzes this conditionality over time, hypothesizing that the effect of EU attitudes on EP vote preferences is catalyzed as EP elections draw closer. In contrast to extant cross-sectional post-election studies, we use a four-wave panel study covering the six months leading up to the Dutch EP elections of 2014, differentiating between party groups (pro, anti, mixed) and five EU attitude dimensions. We find that EU issue voting occurs for both anti-and pro-EU parties, but only increases for the latter. For mixed parties we find no effect of EU attitudes, yet their support base shifts in the anti-EU direction as the elections draw closer. The overarching image, however, is one of surprising stability: EU attitudes form a consistent part of EP voting motivations even outside EP election times.