Emphasise role of Parliaments as decision-making bodies. They might think of other examples of this. Pupils could write an account of a typical day in their lives, and then learn what small details might come under the legislative scope of the Parliament. The different opportunities open to them should be explained. There may be occasions when you do not have the relevant facts to hand, either with teaching colleagues, SMT or pupils.
Pupils can be especially difficult with incessant questions.
The following hints might help you out of potentially awkward situations. Be obscure with your references. This always throws people. Pupils are far too perceptive to fall for such blatant techniques as those described above. That's only for big boys and girls.