In the New Brunswick provincial election of 1991 the Confederation of Regions party captured eight seats and formed the official opposition, bringing to an end decades of traditional two-party dominance. This thesis examines how the electoral breakthrough occurred. Several explanations for Canadian new party development are identified. Their usefulness as a guide to understanding the 1991 New Brunswick election is tested by an examination of the province's political history, with a particular emphasis on the issues surrounding the province's bilingual and bicultural make-up and the evolution of the party system in that context. This is coupled with an analysis of public opinion data collected in 1991. The conclusion dictated by the evidence is that Maurice Pinard's theory of structural conduciveness is the best available explanation. Three of Pinard's structural pre-conditions were present at the time of the election: the political non-representation of social groups through the traditional party system, one-party dominance, and the failure of both traditional parties, in rapid succession, to redress serious grievances. The thesis concludes that CoR fits Pinard's model of a protest party. Its success was due to its ability and willingness to provide institutional representation to Anglophones disenchanted with the course of provincial language policy in the aftermath of the language disputes of the 1980s. As such it is unlikely to pose an enduring threat to New Brunswick's traditional two-party dominant system. Furthermore, the debate over official bilingualism at the provincial level is unique to New Brunswick. Thus CoR's electoral success in New Brunswick cannot be viewed as a warning that it poses any threat to the tradition of two-party dominance in the other Atlantic provinces.