The role of the Monarchy is a back-stop. In English Law all Authority resides with the Sovereign and it is precisely because she rubber-stamps that she still has that Power.
This immensely simple device of channelling all Authority through one person who then lends it out upon receipt of Oaths means that anyone who gets too big for their boots may have their Oath and hence Authority rescinded.
So I would like to demand that:
Any pretensions to Authority or Jurisdiction by any foreign power or potentate within this Realm is Constitutionally Illegal and Void.
This reaffirms the essence of a 1688 Declaration of Rights demand and puts a stake through the heart of any Treaty giving away any hint of Sovereignty.
The monarch used to be a back-stop. In all matters where it has counted, however, the monarch has rolled over and done as she was told. Thus, we are a constitutional monarchy in name only. We need to recognise that, and take the appropriate steps to constrain the powers of the executive. The ones we have are not working.
As to "giving away any hint of Sovereignty" you will see this in my suggestion that "we may assert that no law shall be passed without the active consent of our parliament (requiring thereby a vote), and that no treaty or other device shall obtain which prevents parliament amending, changing or even rejecting a law or a proposal for a law – and that no such law, even when passed, shall stand unless also it is constitutional".