Mr. Chairman, I haven't seen that letter to which the member is referring, but I can understand what it says from what he's read. It is my view—and this is supported by the Speaker's decision on April 27 on the Afghan detainee matter—that the same rule applies with regard to a committee's entitlement to get documents as applies to the committee's entitlement to have persons appear before it. It is not the case that anyone, with three possible exceptions, has a right to not attend when summoned by a committee. Those three exceptions, as you may know, are members of Parliament, senators, and perhaps the Governor General herself. Apart from that, anyone summoned to appear in front of a committee has the obligation to attend.
Now the next stage, however, is where the rubber hits the road. What questions are you entitled to ask that person who does appear in front of you? It is the case, as you well know, that a public servant appearing before committee—and they do this quite frequently—is not to be asked questions relating to ministerial policy or government policy, nor expected to defend ministerial policy and government policy. They are there to respond to the administrative matters of interest to the committee.
In a similar fashion, while I would be of the view that the political staff of a member of Parliament is obliged to attend when summoned and is not necessarily excused from attending by virtue of a direction from his or her minister or the Prime Minister, nonetheless there may be limits to what questions you can put to a political aide. I would say that, analogous to the situation of public servants and so also with political staff, you might use what the lawyers call the best evidence rule, and that is, if what your question is looking for is a matter that the minister can answer best, that is the person to whom the question should be put. On the other hand, if your question is something the aide can answer best, like a matter of fact—were you on this day at this meeting and did you engage in that conversation with so-and-so, which are matters of fact—no one knows those better, arguably, than the aide himself or herself.