Since the UK Supreme Court has ruled that the proroguing of the UK Parliament was illegal, is Boris Johnson personally culpable? Does this depend on whether the UK Parliament and its democratic representatives reconvene themselves? If it is reliant on their reconvening, does the criminality or non-criminality of Boris Johnson or other related parties depend on who took what action, and when and why? Details very useful here.

  • 28
    @PeterDavidCarter an unlawful act is not necessarily a crime.
    – phoog
    Commented Sep 25, 2019 at 15:15
  • 5
    @phoog that's exactly why I asked the question Commented Sep 25, 2019 at 15:15
  • 5
    Unlikely, because he's covered his posterior expertly. He's got a fig leaf in that someone he can reasonably claim was a legal expert told him it was legal, and nothing he said while under oath was provably false -- and when he said things that were provably false, he wasn't under oath. Commented Sep 26, 2019 at 7:35
  • 1
    Not illegal - unlawful - There is a very significant difference here.
    – Baldrickk
    Commented Sep 26, 2019 at 16:05
  • 1
    "Black's Law Dictionary defines unlawful as not authorised by law, while Illegal is defined as forbidden by law." So if someone does something unauthorised, that's unlawful and their actions have no legal validity, but they can only be punishable if there was a law expressly making it illegal and defining penalties for breaking that law. Commented Sep 27, 2019 at 19:27

6 Answers 6




The notion of unlawful here means only that the prorogation does not comply with how the supreme court interprets the political rule book.

It doesn't actually mean any actual law was broken, or anything criminal occurred.

It is no different than saying, a law is unconstitutional. legislators who draft laws deemed unconstitutional by the US Supreme Court (which happens all the time) never face criminal charges. Because unconstitutional there only means it doesn't follow how the court interprets the constitution.

  • 1
    What do you mean by "actual law"? It's a fuzzy concept in common law systems.
    – phoog
    Commented Sep 25, 2019 at 15:34
  • 4
    Making unconstitutional laws, passing unconstitutional laws, and even upholding (ultimately) unconstitutional laws is not a criminal offense, is not even a civil offense, is not an offense of any kind. what Boris did was a procedural move, and the referee deemed that unlawful. So he just has to make a different move. Commented Sep 25, 2019 at 16:45
  • 2
    Still really not clear on how a ruling of unlawful means a law wasn't broken. Clearly it was. It might not be a criminal one, but clearly, clearly if a supreme course rules something was unlawful then a law was broken Commented Sep 25, 2019 at 19:48
  • 3
    "a decision to prorogue Parliament (or to advise the monarch to prorogue Parliament) will be unlawful if the prorogation has the effect of frustrating or preventing, without reasonable justification, the ability of Parliament to carry out its constitutional functions as a legislature and as the body responsible for the supervision of the executive. In such a situation, the court will intervene if the effect is sufficiently serious to justify such an exceptional course." <- the law that was broken Commented Sep 25, 2019 at 21:22
  • 1
    @PeterDavidCarter: I don't think that follows in general. Hypothetical example, if the Speaker forgets to say "Simon says" at the right time then some proceeding of the House of Commons might eventually be struck down as unlawful. It wouldn't mean the law was broken, though, merely that what the House spent that time doing was legally ineffective. But sure, in this case, the ruling does speak to Johnson having an illegitimate purpose in advising a 5-week prorogation. Commented Sep 27, 2019 at 15:13

IANAL, but probably the only thing he could be charged with is misconduct in public office. I haven't seen anyone suggest that he should be charged (for this, this time).

The charge does not require one to break some explicit statute. It also applies "where there is no relevant statutory offence, but the behaviour or the circumstances are such that they should nevertheless be treated as criminal". The criteria are:

  • a public officer acting as such;
  • wilfully neglects to perform his duty and/or wilfully misconducts himself;
  • to such a degree as to amount to an abuse of the public's trust in the office holder;
  • without reasonable excuse or justification.

However, last time Johnson was charged with this offence, by a private prosecutor, and for some political statements, it failed fairly quickly, when the granting of summons was appealed to the High Court.

Of course, the circumstances this time involve more than a statement, but insofar I haven't seen suggestions that he should be charged.

I don't know if the following argument meets all the legal criteria to be a good defence, but conceptually at least, the fact that the High Court of England ruled in favor of Johnson's government, could be used as an argument that "hey, it wasn't obviously unlawful before the Supreme Court decided so", i.e. this could be a valid excuse under bullet #4 from the criteria above.


While this is a small difference, the supreme court found that the prorogation was unlawful rather than illegal. This may seem pedantic, but the law is often so. Boris will not be charged with a crime, because there is no crime to charge him with.

It is possible that he will break a law over this, but until he has done so it is impossible for charges to be brought.

  • 1
    I suppose the next question is: should it be a crime to 'prorogue' parliament on false premises, given the UK is supposed to be a democratic country. Sorry for the leading question here... Commented Sep 25, 2019 at 15:18
  • 5
    @PeterDavidCarter Well again, there is a terminology problem with your follow up. Parliament was not dissolved (nor did Boris attempt to dissolve it). An attempt was made to prorogue parliament, but this is a very different act to dissolving it. Dissolving parliament happens just before a General Election, prorogation normally happens once a year. Prorogation ends the session within a Parliament, dissolving ends a Parliament. Commented Sep 25, 2019 at 15:22
  • 4
    It could be argued that this is closer to ultra vires - i.e. the PM has the power to advise the Queen to prorogue parliament, but the court found that that power has limitations on its use; and in this instance the PM exceeded those limitations. As far as I can tell, the only penalty for a government or company which exceeds its legal authority in this way is for any such acts to be reversed - which is exactly what has happened here. Commented Sep 25, 2019 at 15:52
  • 2
    @PeterDavidCarter There is no legal definition of what the relevant premises are. The only reason for this whole legal affair is that one or two unelected private individuals (e.g.Gina Miller) chose to make a fuss about it. Creating the Supreme Court at all was just importing one of the worst features of the US system into the UK, IMO.
    – alephzero
    Commented Sep 26, 2019 at 11:20
  • 5
    @alephzero, you seem to be overlooking the Scottish case, which was brought by more than 10% of elected MPs. Commented Sep 26, 2019 at 16:19

Highly unlikely

Most high courts (regardless of country) prefer to keep themselves out of the political process. When cases like this come up, they want to tailor things as narrowly as possible as to the question before them. In this case, the UK Supreme Court said this (trimmed for relevance)

The power to prorogue is limited by the constitutional principles with which it would otherwise conflict. For present purposes, the relevant limit on the power to prorogue is this: that a decision to prorogue (or advise the monarch to prorogue) will be unlawful if the prorogation has the effect of frustrating or preventing, without reasonable justification, the ability of Parliament to carry out its constitutional functions as a legislature and as the body responsible for the supervision of the executive. In judging any justification which might be put forward, the court must of course be sensitive to the responsibilities and experience of the Prime Minister and proceed with appropriate caution.

If the prorogation does have that effect, without reasonable justification, there is no need for the court to consider whether the Prime Minister’s motive or purpose was unlawful

The third question, therefore, is whether this prorogation did have the effect of frustrating or preventing the ability of Parliament to carry out its constitutional functions without reasonable justification. This was not a normal prorogation in the run-up to a Queen’s Speech.

No justification for taking action with such an extreme effect has been put before the court.

The Court is bound to conclude, therefore, that the decision to advise Her Majesty to prorogue Parliament was unlawful because it had the effect of frustrating or preventing the ability of Parliament to carry out its constitutional functions without reasonable justification.

This Court has already concluded that the Prime Minister’s advice to Her Majesty was unlawful, void and of no effect. This means that the Order in Council to which it led was also unlawful, void and of no effect and should be quashed. This means that when the Royal Commissioners walked into the House of Lords it was as if they walked in with a blank sheet of paper. The prorogation was also void and of no effect. Parliament has not been prorogued. This is the unanimous judgment of all 11 Justices

The question here was one of procedure. Trying to make this criminal would create all sorts of chaos. What laws would he be guilty of breaking? What sentence should be carried out? Could the Supreme Court have all of Parliament arrested for violating parliamentary procedures


The High Court nullified the order to prorogue. It did not accuse Mr. Johnson of having committed a crime, only having broken the procedures of Parliament.


At this point the court has not ruled that what he did was illegal, only that it did not comply with the laws of the land and thus should be voided.

If he tries to prorogue again or refuses to follow the law created by the Ben Act (to request an extension from the EU) he could be ordered by the court to do so and then held in contempt of court if he didn't.


Yes, but only if he tried the same thing twice

The courts of law are unlikely to rule this matter criminal in the first instance. However, if Boris Johnson were to try the same thing again, or were to attempt to disrupt the reconvening of parliament, he likely would be found in contempt of court, which is a criminal offense.

  • 4
    Do you have any evidence for this supposition?
    – deep64blue
    Commented Sep 26, 2019 at 13:32
  • 1
    Unlikely as the court did not issue an injection against him. Without question they would issue an injection if they had reasons to think he would disrupt the reconvening of parliament, then if he did, it would be contempt of court. Commented Sep 26, 2019 at 15:08

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .