I 'm working on the pragmatic function of interrogatory clauses in parliamentary discourse. In the course of my literature review, I have come across several subdivision of interrogative clauses/sentences. Many of these subdivisions are overlapping.
I (Shammas, 2002) wrote on this. To answer from the top of my head, I would say that questions can be similar to jokes in that they imply certain meanings that the speaker/writer would not venture to put into plain words in a direct way. A question is not always intended to seek information. It is, in fact, quite often, in both Arabic and English (and perhaps in other or all languages), meant to state something but in a somewhat polite way. This cab referred to as a mitigating device. For instance, when you want to raise a kind of objection, you say, "What about changing the place?" or "Don't you think that ...?", etc. In short, an interrogative question is a linguistic unit normally used by native or near-native speakers to suggest, object, modify or initiate an attempt to convince the hearer of something s/he would not in the normal circumstances.
1. rhetorical questions (addressed to the parliament or to the government), and
2. 'real' questions (addressed to the government).
In the parliamentary discourse in the stricter sense (Nr. 1), I suppose there appear no 'real' questions. -
If you want to find out the functions of rhetorical questions in parliament, you should read what has been written about rhetoric from the old times till nowadays. The art of rhetoric was, as we know, invented for the production of speeches within court cases/trials. I think there is no great difference between the discourses in parliament and those in trials.
You may want to look at the pragmatics of the interrogatives in parliamentary discourse in terms of what speech acts they create, using Austin (1962) and Searle (1969) well known schemes to pragmatists. You may also want to look at them through Grice's maxims.