There is no doubt a way in which a republican can join the Privy Council. The "firm" at buck house are good at making things work. In a democracy they would have to make allowances for this. Having said that and having read Luckygirl's link it seems a complete waste of time and money and should be abandoned as far as I can see.
Ana where does it say that Cameron "was sworn just over a week after becoming Tory leader". Everything I have read says three months. Also you say "Strange that no one seems to know what this mysterious 'prior engagement' is..." Apparently it is a private appointment so no business of any of us.
34 year old assisted euthanasia