My experience is that most ministers wouldn't mind that and would in fact obey that. That's the most important part. I guess the question is when we get a minister who says no. Then I guess we can say, “Well, then, don't come.”
Evidence of meeting #1 for Environment and Sustainable Development in the 39th Parliament, 2nd Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was chair.
A recording is available from Parliament.