The principle of proportionality implies that the dual voting system is not justified if other measures to ensure participation of minorities in public life exist which do not impinge, or impinge less, on other voters' right to equal suffrage. The possibility to apply these other measures should be taken into account. However, the mere fact that other measures than dual vote exist, and indeed have been adopted by other States, does not call for the conclusion in abstracto that the dual vote is unacceptable as such. Nevertheless when the pursued aim may be reached by such other measures, dual voting will not pass the test of proportionality.