The article, which is an investigation part of the grant program Erasmus+, Jean Monnet Project European Antitotalitarian Practices (№ 599704-EPP-1-2018-1-UA-EPPJMO-MODULE), is devoted to the research of dialogical interaction of speakers in the parliaments of Great Britain, Germany and Ukraine held in the format of political debates. In this comparative study, the phases of parliamentary debates unfolding, their functional purposes, and the features of verbal outlining of this social interaction were established, and both isomorphic and allomorphic features were found out. The parliamentary debates are a kind of political argument between political subjects in the ethnic parliament who persuade each other in the rightfulness of their position while passing a law. The main purpose of it, however, is to influence a mass addressee, the potential electorate, via mass media. This communicative event in the format of ethnic parliamentary debates is analyzed with the help of frame analysis, the method of cognitive linguistics. Such a choice is stipulated by two facts. Firstly, it is determined by modern linguistic demands as for the language and speech facts investigation. And, secondly, frames as cognitive structures that keep information about various events, the ways of its successful implementation in familiar situations while working out a necessary strategic-and-tactic line of communicative behavior, turn out to be a rather effective instrument of political communication analysis. It has been established that the debates in the countries mentioned above possess a common structural-compositional construction, similar phases of dialogical interaction fixed in such slots as THE BEGINNING OF THE DIALOGUE, THE PROGRESS OF THE DIALOGUE, and THE END OF THE DIALOGUE of the frame scenario THE PARLIAMENTARY DEBATES. Each phase and its constituents are regulated and have specific tasks as the parts of the only aim – an approval of law projects and influence on the mass audience. The differences of the debates unfolding are predetermined by their content, the traditions, and rules of their realization as well as by the norms of communicative behavior of representatives of these ethnic communities.