The use of partisan heuristics is known to be an important explanatory factor to understand individuals’ political preferences. However, the role of negative party identification on the use of partisan heuristic remains unclear and understudied. Moreover, while some research find that political awareness increases the use of partisan cues, the causal relationship between political awareness and the use of partisan cues remains questionable. In this research we try to investigate the use of partisan heuristic for positive and negative party identification and the influence of political awareness on the use of partisan heuristics. With an experimental design based on direct democratic ballots, this research aims to show the causal relationship between party support, party position and vote intention for direct democratic proposals. Our results suggest that voters might take cues from negative and positive party identification and that political awareness might play a more ambiguous role on the use of partisan heuristics than argued in previous research.