www.supremecourt.uk/cases/docs/uksc-2019-0192-judgment.pdf
Adam Wagner has highlighted the following sections from the ruling:
His analysis below (his bold below. Italic is ruling. All other comment is Wagner)
Adam Wagner @AdamWagner1
As I said it would be, the key concern of the court was that if it couldn't exercise jurisdiction (consider a prorogation decision) that would be the thin end of the wedge. I expect that the leak from Boris's office about proroguing again would have focussed minds.
42. The sovereignty of Parliament would, however, be undermined as the foundational principle of our constitution if the executive could, through the use of the prerogative, prevent Parliament from exercising its legislative authority for as long as it pleased. That, however, would be the position if there was no legal limit upon the power to prorogue Parliament (subject to a few exceptional circumstances in which, under statute, Parliament can meet while it stands prorogued). An unlimited power of prorogation would therefore be incompatible with the legal principle of Parliamentary sovereignty.
Difficult to emphasise how important and unusual it is for 11 justices to be unanimous. Nobody predicted this. Everyone, even the most gung ho lawyers thought there would be a majority
The Prime Minister through his brazen unconstitutional behaviour has woken a sleeping giant
Second principle in play: parliamentary accountability (as opposed to sovereignty)
"the longer that Parliament stands prorogued, the greater the risk that responsible government may be replaced by unaccountable government: the antithesis of the democratic model."
48. That principle is not placed in jeopardy if Parliament stands prorogued for the short period which is customary, and as we have explained, Parliament does not in any event expect to be in permanent session. But the longer that Parliament stands prorogued, the greater the risk that responsible government may be replaced by unaccountable government: the antithesis of the democratic model. So the same question arises as in relation to Parliamentary sovereignty: what is the legal limit upon the power to prorogue which makes it compatible with the ability of Parliament to carry out its constitutional functions?
Here is the clever wheeze by which court avoids directly examining motives of the Prime Minister. It looks only to justification for prorogation, and the question of whether it is "reasonable" is an objective rather than subjective one. That means it doesn't matter what PM thinks
51. That standard is one that can be applied in practice. The extent to which prorogation frustrates or prevents Parliament’s ability to perform its legislative functions and its supervision of the executive is a question of fact which presents no greater difficulty than many other questions of fact which are routinely decided by the courts. The court then has to decide whether the Prime Minister’s explanation for advising that Parliament should be prorogued is a reasonable justification for a prorogation having those effects.
So the burden of proof is shifted to the Prime Minister to provide a "reasonable justification" (what is 'reasonable' in the courts is an objective question, so the purported justification will be examined in the round) and if s/he can't, the prorogation is unlawful
The Prime Minister’s wish to end one session of Parliament and to begin another will normally be enough in itself to justify the short period of prorogation which has been normal in modern practice. It could only be in unusual circumstances that any further justification might be necessary. Even in such a case, when considering the justification put forward, the court would have to bear in mind that the decision whether to advise the monarch to prorogue Parliament falls within the area of responsibility of the Prime Minister, and that it may in some circumstances involve a range of considerations, including matters of political judgment. The court would therefore have to consider any justification that might be advanced with sensitivity to the responsibilities and experience of the Prime Minister, and with a corresponding degree of caution. Nevertheless, it is the court’s responsibility to determine whether the Prime Minster has remained within the legal limits of the power. If not, the final question will be whether the consequences are sufficiently serious to call for the court’s intervention.
Here is the court's summary on justiciability.
52. Returning, then, to the justiciability of the question of whether the Prime Minister’s advice to the Queen was lawful, we are firmly of the opinion that it is justiciable. As we have explained, it is well established, and is accepted by counsel for the Prime Minister, that the courts can rule on the extent of prerogative powers. That is what the court will be doing in this case by applying the legal standard which we have described. That standard is not concerned with the mode of exercise of the prerogative power within its lawful limits. On the contrary, it is a standard which determines the limits of the power, marking the boundary between the prerogative on the one hand and the operation of the constitutional principles of the sovereignty of Parliament and responsible government on the other hand. An issue which can be resolved by the application of that standard is by definition one which concerns the extent of the power to prorogue, and is therefore justiciable.
Supreme Court here laying out the ABC of the UK's constitution. This is directly aimed at the Prime Minister. Lady Hale has the big colourful markers out here.
55. Let us remind ourselves of the foundations of our constitution. We live in a representative democracy. The House of Commons exists because the people have elected its members. The Government is not directly elected by the people (unlike the position in some other democracies). The Government exists because it has the confidence of the House of Commons. It has no democratic legitimacy other than that. This means that it is accountable to the House of Commons - and indeed to the House of Lords - for its actions, remembering always that the actual task of governing is for the executive and not for Parliament or the courts. The first question, therefore, is whether the Prime Minister’s action had the effect of frustrating or preventing the constitutional role of Parliament in holding the Government to account.
Here is the key paragraph on the factual question of whether prorogation did in fact have effect of preventing parliamentary scrutiny of Executive.
The answer is it did for 5 out of a possible of 8 weeks. Brexit context crucial as we really need Parliament during this period
56. The answer is that of course it did. This was not a normal prorogation in the run-up to a Queen’s Speech. It prevented Parliament from carrying out its constitutional role for five out of a possible eight weeks between the end of the summer recess and exit day on the 31st October. Parliament might have decided to go into recess for the party conferences during some of that period but, given the extraordinary situation in which the United Kingdom finds itself, its members might have thought that parliamentary scrutiny of government activity in the run-up to exit day was more important and declined to do so, or at least they might have curtailed the normal conference season recess because of that. Even if they had agreed to go into recess for the usual three-week period, they would still have been able to perform their function of holding the government to account. Prorogation means that they cannot do that.
Moving backwards for a second, & zooming out to wider political (even democratic) context, this is the danger paragraph for the court. Says (correctly) that since we have an unwritten constitution, it is for court to take responsibility for determining "legal limits" of powers
39. Although the United Kingdom does not have a single document entitled “The Constitution”, it nevertheless possesses a Constitution, established over the course of our history by common law, statutes, conventions and practice. Since it has not been codified, it has developed pragmatically, and remains sufficiently flexible to be capable of further development. Nevertheless, it includes numerous principles of law, which are enforceable by the courts in the same way as other legal principles. In giving them effect, the courts have the responsibility of upholding the values and principles of our constitution and making them effective. It is their particular responsibility to determine the legal limits of the powers conferred on each branch of government, and to decide whether any exercise of power has transgressed those limits. The courts cannot shirk that responsibility merely on the ground that the question raised is political in tone or context.
One might argue (as I do here newstatesman.com/politics/brexit/2019/09/week-supreme-court-must-come-age) that as the court becomes more embroiled in issues which may be 'legal' but are also 'high politics', it is time for a wider democratic settlement of these principles. ie. a written constitution
Parliament had a right and a duty to be involved in the preparations for Brexit. Not politics, constitution. End of.
57. Such an interruption in the process of responsible government might not matter in some circumstances. But the circumstances here were, as already explained, quite exceptional. A fundamental change was due to take place in the Constitution of the United Kingdom on 31st October 2019. Whether or not this is a good thing is not for this or any other court to judge. The people have decided that. But that Parliament, and in particular the House of Commons as the democratically elected representatives of the people, has a right to have a voice in how that change comes about is indisputable
Here Supreme Court says it isn't concerned with PM's motives but his stated reasons. Clever. Avoid having to say he's a liar, but does say his reasons are insufficient. In fact, he gave no reason at all for length of prorogation.
Might as well have called him a liar really
58. The next question is whether there is a reasonable justification for taking action which had such an extreme effect upon the fundamentals of our democracy. Of course, the Government must be accorded a great deal of latitude in making decisions of this nature. We are not concerned with the Prime Minister’s motive in doing what he did. We are concerned with whether there was a reason for him to do it. It will be apparent from the documents quoted earlier that no reason was given for closing down Parliament for five weeks. Everything was focussed on the need for a new Queen’s Speech and the reasons for holding that in the week beginning the 14th October rather than the previous week. But why did that need a prorogation of five weeks?
Here the Supreme Court is putting on its unimpressed face at Nikki da Costa's memorandum.
And it's super unimpressed face that there isn't a "hint" that the PM took his constitutional responsibility seriously
The end of para 60 is 🔥🔥🔥
The Prime Minister’s reaction was to describe the September sitting as a “rigmarole”. Nowhere is there a hint that the Prime Minister, in giving advice to Her Majesty, is more than simply the leader of the Government seeking to promote its own policies; he has a constitutional responsibility, as we have explained in para 30 above.
Smart move. PM didn't give any reason for the length of prorogation, let alone a lawful one.
"We cannot speculate, in the absence of further evidence, upon what such reasons might have been"
Supreme Court a fan of cake (not saying he lied) and of eating cake (implying he lied)
61. It is impossible for us to conclude, on the evidence which has been put before us, that there was any reason - let alone a good reason - to advise Her Majesty to prorogue Parliament for five weeks, from 9th or 12th September until 14th October. We cannot speculate, in the absence of further evidence, upon what such reasons might have been. It follows that the decision was unlawful.
Moving on to remedy (what will the court do to make things good)
Govt argued that declaring prorogation null would be contrary to the British Bill of Rights 1689 which prevents the courts getting involved in a 'proceeding in parliament'
64. Article 9 provides:
“That the Freedome of Speech and Debates or Proceedings in Parlyament ought not to be impeached or questioned in any Court or Place out of Parlyament.”
Here's why the prorogation isn't caught by section 9 of the Bill of Rights. It's imposed upon parliament from the outside. Neat!
68. The prorogation itself takes place in the House of Lords and in the presence of Members of both Houses. But it cannot sensibly be described as a “proceeding in Parliament”. It is not a decision of either House of Parliament. Quite the contrary: it is something which is imposed upon them from outside. It is not something upon which the Members of Parliament can speak or vote. The Commissioners are not acting in their capacity as members of the House of Lords but in their capacity as Royal Commissioners carrying out the Queen’s bidding. They have no freedom of speech. This is not the core or essential business of Parliament. Quite the contrary: it brings that core or essential business of Parliament to an end.
And here is the firework which explodes at the end of the judgment. Since the advice to prorogue was outside of the Prime Minister's powers, it is as if he never gave it, and there was no decision, and prorogation never happened!
Parliament is BACK! As if by legal magic
70. It follows that Parliament has not been prorogued and that this court should make declarations to that effect. We have been told by counsel for the Prime Minister that he will “take all necessary steps to comply with the terms of any declaration made by the court” and we expect him to do so. However, it appears to us that, as Parliament is not prorogued, it is for Parliament to decide what to do next. There is no need for Parliament to be recalled under the Meeting of Parliament Act 1797. Nor has Parliament voted to adjourn or go into recess. Unless there is some Parliamentary rule to the contrary of which we are unaware, the Speaker of the House of Commons and the Lord Speaker can take immediate steps to enable each House to meet as soon as possible to decide upon a way forward. That would, of course, be a proceeding in Parliament which could not be called in question in this or any other court.^