Since this is my motion, I'd like to speak to it.
In my opinion, a summons to appear can be very legal and formal, but it can also be a letter inviting witnesses.
Clerk, you spoke to the witnesses by telephone. They told you that they could be here if the others were as well; one other witness said that he would discuss the matter with his lawyer and that he would see. So we have no assurance that certain witnesses won't let us down in the next two weeks. I want us to be sure that the witnesses who said they are available appear before the committee.
I want to trust people. In my view, everyone is beautiful, everyone is nice, except when they don't all react in the same way. I don't want the witnesses to withdraw following certain reactions or discussions. On the one hand, I want to summon them, and on the other hand, I want us to ensure that we have changed the agenda concerning our meeting schedule.