I consider a two-party parliamentary election where parties compete on a quality (or valence) dimension. First I motivate why in such an election a voter may decide to cast a blank vote. Second I define a new voting system, inspired in the standard proportional representation system, where the percentage of blank votes is translated into vacant seats in the parliament. I analyze party competition assuming adapted versions of the models of “Bertand” and “Cournot”. I compare the equilibrium outcomes on parties’ quality and profits obtained with both the alternative proportional system and the standard one. I show that society and parties may have interests in conflict.