Is our Prime Minister really this dense?

The British constitution relies on reference to precedent, recorded in accounts of legal cases. Unwritten as a single document but not non-existent.

Perhaps it's just as well that much of our constitution is unwritten. Any attempt to formulate it would take many years of royal commissions which would change their terms of reference with every change of government. And, in the end (if there was one) come to no very definite conclusion.