This thesis argues that the aggressive and informal style of discourse used in Thai parliamentary debates is a product of the Thai political sphere, serving clear functions In its context. Adopting the approach of Critical Discourse Analysis, the thesis presents discourse as socially constituted as well as socially constitutive. The research employs a two level analysis to explore this hypothesis. At the macro level, Critical Discourse Analysis and the Sociocognitive Approach are operationalised to investigate the socio-political conditions that prompt this 'unparliamentary' mode of parliamentary discourse. At the micro level, politeness theory and pragmatics are
employed to investigate the potential functions that small linguistic features may serve under such social conditions. Five sample accusatory speeches and two sample respondent speeches from recent debates are selected for close textual analysis using this approach.
It is argued that the unparliamentary style of the debates' discourse is the result of discursive strategies used in politicians' speeches. These strategies are textual evidence of sociocultural practice and discourse practice. They reflect the speakers' attempts to subvert three competing conjunctures in the Thai political domain: the debate's formal and actual purposes, its Code of
Behaviour, and its multiple audiences. Debaters need to balance three contending purposes: the desire of highly partisan participants to cause maximum damage to the opposing side, their attempts to seek public support (including the maintenance of face), and their need to stay within the parliamentary Code of Behaviour.
This thesis identifies a number of strategies that potentially serve these conflicting purposes, for
example, intertextuality, enthymeme and prolepsis/disclaimer. These findings lead to the
conclusion that an unparliamentary debating style, constituted of small, seemingly insignificant
linguistic features, carries larger social implications. Despite being a reflection of social conditions, this debating style has the potential to redefine these conditions. Thai no-confidence debates offer an accomplished parliamentary speaker the opportunity to achieve apparently contradictory political and linguistic ends, within the same tightly-crafted speech.