Absolutely, but the point being, in our submission anyway, and maybe I don't even have to get into this because we are not revisiting the 1972 Act; that is a matter on which Lord Pannick has argued his case. We say he is right. But in any event, we do respectfully submit that the -- sorry, my Lord -- we do respectfully submit that the construction of the Government of Wales Act 2006 is all of a piece or is likely to be considered to be all of a piece with interlocking legislation. We say that interlocking legislation gives the clue, or actually it decides certainly in our favour what the Government of Wales Act means, but it may be useful in your Lordships and your Ladyship looking at what the 1972 Act means.
My Lord, may I then move on to say this, that if we are right in this suggested analysis and if your Lordships were with us on the point of construction on the 1972 Act and/or the Government of Wales Act, and/or, I should add, taking up Lord Carnwath's point, any of the other principles that Lord Pannick has developed and articulated, and ditto for Mr Chambers, as far as, then we cannot see how the De Keyser line of cases has any relevance to these appeals.
They are analytically irrelevant because nothing is being abrogated and picking up the language of clamp to deconstruct it, nothing is being clamped because there is nothing to clamp. The principle of non-dispensation has already aborted the possibility of using prerogative power in that way.
So if we are right so far, the difficulties for my learned friend Mr Eadie go even further, because he has not put forward any competing principle. What was astonishing in the divisional court -- we were spectators there because we had a noting brief, we were noting down what was said; at one stage in the argument in the divisional court, Mr Eadie was suggesting to the divisional court that they should prefer the De Keyser line of case law over the common law principle of legality, but if the De Keyser line of cases is analytically irrelevant, there is nothing to compete with all the principles that have been articulated so far.
What we say is that these points all crystallised when, on the first day, my learned friend Mr Eadie was asked: isn't it important -- asked, I think, by Lord Sumption -- isn't it important to know what we are talking about. The answer is in the transcript, but we had understood Mr Eadie simply to go back in circular fashion to say: well, it is a very wide power; in other words he didn't put forward anything that I can deconstruct because there is nothing to deconstruct.
So that is stage one of my submissions. The fault line running through the Government's whole argument.
The second area that I just wanted to make a few points about is the constitutional principle at stake. Of course in one sense we all think we know what the constitutional principle at stake is. But may I suggest two broad questions which your Lordships and your Ladyship may wish to consider in analysing all these cases, and they are at a very high level, a very general level.
First of all, is there a fundamental constitutional principle against which the legality of using the prerogative can be tested, an overarching principle, and this court knows what I have suggested.
Secondly, and this is where Sewel comes in, excuse me, independently of the answer to that question, how should the common law approach the legal scope of the treaty-making prerogative in a context such as this?
What I mean by that is, there is no doubt whatever that even if none of the principles I contended for were relevant, that is to say the non-dispensation principle hadn't been breached, none of the other principles had been breached, we are still looking at a situation in which prerogative power is being sought to be used to drive through the most major constitutional change in our system for -- at least since 1972.
One has to analyse, one has to put it in this way, which is the way we do put it, we do not put Sewel in the way that the learned Lord Advocate does. Nothing I say is intended to diminish any of his submissions, any of the force of his submissions.
What we do say is that when one is lacking at the legal scope of prerogative power, it is essential to analyse it against a common law framework. Whether or not the prerogative is a creature of the common law, undoubtedly its limits are bounded by the common law, and there are many ways in which the scope of prerogative power can be tested against common law thresholds.
One threshold is what the books say, and I am not going to repeat the Diceyian views which now have become perhaps something of a cliche, but are nonetheless important, but the prerogative power is residual. It does not mean it is not important, but it is residual.
One looks at the books first of all to consider what are the criteria of determining the legal scope of prerogative power, but one looks and I agree, we agree with my learned friend Mr Eadie about this, one looks at the fact that we are in a modern evolving constitution.
In the last 50 years or so, it is axiomatic that we have developed a constitutional consciousness; witnessed the development of the common law notion of constitutional statutes; witnessed since 1960 the development of modern judicial review; witnessed the bringing into force of the Human Rights Act. But most of all from our perspective, witnessed the emerging and fragile, at the moment, devolutionary development. And then look at the trajectory of the prerogative against the trajectory of these developments.
We respectfully submit, and one doesn't need to go into detailed documents to arrive at this conclusion, that the prerogative is declining; there is undoubtedly a wish, we see it as recently as 2008, the Brown Government wanted to make all prerogative powers statutory at one stage. Indeed, I think Ms Mountfield and I were both on a committee which had to respond to a consultation.
The prerogative measured against the trajectory of devolution simply does not match, and yet what is being said here is that as a matter of common law, the prerogative can be used, as I say, without any recourse to Parliament, to drive through the most major constitutional change certainly of the last, I would say, 40 years.
It has become the motor of our constitution, rather than the secondary residual power, but this fits in very much to our argument about Sewel, which I want to make in this way.
Sewel is a convention, nobody doubts it. The convention, and I will use this phrase again, I am sorry because I am fast forwarding to what I am going to say later but the convention is a very important force, constitutional force in our society. The reason why it is such a constitutional force is that it is the glue and the only glue that can really hold an unwritten constitution together.
We do not have rules, we have laws, we have an aggregation of laws. How does our constitution develop? It develops through incremental practices, and the Sewel convention in the emerging context of devolution is a very important constitutional force. We say, when we get to it, that the courts, the common law, can take cognisance of conventions in a way that has nothing to do with the legal enforceability of those conventions and, with great respect to the advantage Scotland has over us in one sense, has nothing to do with whether it is in a statute. But if it is in a statute, and it soon will be in the Government of Wales Act, we think, if that happens, that shows the way things are beginning to solidify.
So can I come back to what at heart these appeals are really about. They are really about the proper distribution of power between Parliament and the executive in our society. What I wanted to say was each of the organs, each of the institutions of our state, of our constitution, play complementary roles; no one dominates the other but each one dominates the other in its own sphere.
So the judiciary are the total judges of the interpretation of law and the development of the common law. The executive is totally supreme in giving effect to policy, provided that policy is enshrined in law. And Parliament is supreme in making law.
That is why the overarching principle that I have tried to articulate, under the broad umbrella of the non-dispensing principle, is so important; and the legislative supremacy of Parliament over the executive is an axiom in our society. Indeed, my Lord, Lord Neuberger, in a case decided as recently as 13 July this year, in the context of subordinate legislation said this. It is the Public Law Project case, paragraph 23:
"In declaring subordinate legislation to be invalid, the court is upholding the supremacy of Parliament over the executive."
So, my Lords, what is really clear, if one just has one's feet on the ground for a moment, in the context of the Brexit vote, the Brexit vote split the United Kingdom. It split it into four parts. We have absolutely no quarrel with the vote. It is an United Kingdom vote. And it is a majority for the implementation of Brexit. But the point is this. It is almost the most divisive political event that has happened over the last several decades, and who is going to judge what happens next, according to law?
In our submission, whether one approaches this matter from the perspective of the dispensing principle, or whether you approach this matter from the perspective of the common law, it must be Parliament. All the recent events have nothing to do with this case, in particular, and I say it very respectfully, but in particular the Referendum Act of 2015 has absolutely nothing to do with the legal issues in this case.
The referendum results, I think, was discussed in argument yesterday. It is a statute that has died, it has fulfilled its purpose and you cannot revive a corpse by tearing up the death certificate. You cannot revive the 2015 Act and give it a separate purpose, which is to in some way become a normative statute, because to do that is to give a statutory power and not a prerogative power. There is nothing in the 2015 Act that can say anything sensible about the prerogative.