In every region of the country, modern British party systems now involve at least six or seven parties with significant vote shares at one election or another, a potential for legislative representation at some level, office-seeking capabilities and endurance over time, and distinctive ideological positions which are not encompassed by Labour versus Conservative differences. Whenever voters exercise their choices in proportional systems of voting (which do not forcibly suppress some preferences) they assign significant support to at least six or seven parties, as in the 2004 European election when electors in the median British region supported 5.3 effective parties. Under the current ‘coexistence’ of PR and plurality rule voting systems, the outcomes of PR elections have already exerted an important influence upon the development of ‘major’ party politics. The UK seems to closely fit a general pattern amongst liberal democracies for Duverger’s Law to hold for the ‘wrong’ reasons. Here an increase in the effective number of parties occurs first and then it later induces incumbent political elites to shift away from plurality rule to a proportional system in order to defend their declining positions. Hence the subsequent introduction of PR does not generate any further multi-partism, but simply consolidates a change that has already happened. To effectively understand contemporary changes in the UK, political scientists and other commentators need to completely abandon the anachronistic ‘legacy’ conceptual apparatus of a ‘two-party system’ and the assumption that voting for a party necessarily betokens positive support. Instead we need to focus on how party competition works in an era where increasingly ‘dealigned’ voters have multiple preferences, activated in different ways at different contests, and imposing fundamental changes in how parties campaign and choose strategies from one contest to another.