Some conventions can be enforced in the courts, and I believe that the confidence convention could be. But many conventions are simply what one might call a condensation of expert opinion on what actually happened in the past, and that is open to contestation. That is why I emphasize that, in my view, yes, we have the power in the Canadian Parliament to legislate on prorogation and to define its terms, but other people argue the other side.
On May 4th, 2010. See this statement in context.