Is there only one way to achieve Proportional Representation?
No, there are numerous voting systems that will provide proportional representation. STV is unique in that it does not only ensure each political party receives its fair share of seats but it also provides proportionality on any criteria which the voters feel is important. For example if 75% of people voted for pro-European candidates then pro-European candidates would fill about 75% of the seats. This principle will hold true for any decision(s) which the voters feel matter to them.
