This power is not often exercised. We're talking here about interim orders, about situations in which another department may be involved. The Department of the Environment is responsible for ensuring that the department in question does not take on this responsibility. If memory serves me well, this measure has only been invoked twice since 1988, and in both cases, the department maintained its authority. As I see it, this provision merely ensures that two departments will not resort to the same action at the same time.
On December 11th, 2006. See this statement in context.