[matthewheath]

> Would it be illegal to make a law whose punishment was an oubliette?

No, it would not be illegal to make a law whose punishment was an oubliette. The British Parliament is sovereign and supreme, and can make any law it wishes.

The devolved legislatures are limited by the Act(s) establishing them. Such a law passed by the Scottish Parliament would probably be challenged under S29(2)(d) of the Scotland Act 1998 which prohibits breaches of the European Convention on Human Rights.

In this case, such a law in Scotland could potentially breach Article 3 of the Convention which prohibits inhuman or degrading punishment. The British Parliament can simply choose to ignore it, but the Scottish Parliament can't (unless the British Parliament chose to give it such powers).

> Can the queen be detained at her own pleasure, at least for anything other than the detonation of a nuclear device in her personal capacity?

No, she cannot be prosecuted for anything while she is the monarch. She would need to abdicate or otherwise be legally removed (e.g. an Act of Parliament abolishing the Crown) from her position.

Even if she were able to be prosecuted, the Nuclear Explosions (Prohibition and Inspections) Act 1998 is not currently in force, and even if the Act were in force, Her Majesty would be exempt under S14(4):

"Nothing in this section affects Her Majesty in her private capacity; and this subsection shall be construed as if section 38(3) of the Crown Proceedings Act 1947 (meaning of Her Majesty in her private capacity) were contained in this Act."

[growse]

> No, it would not be illegal to make a law whose punishment was an oubliette. The British Parliament is sovereign and supreme, and can make any law it wishes.

Sure, but this is the same argument that comes around whenever previously signed treaties become 'inconvenient'.

Parliament can, of course, choose to ignore EHCR/Geneva/pick-any-other-ratified-treaty. But there are both predictable and unpredictable consequences for doing so, so in practice it's prudent for parliament to not just wield their unlimited power to just start murdering whoever they fancy.

[matthewheath]

I think prudence really depends on the whim of the executive, since generally the executive is Parliament given the majority it normally possesses. A number of British governments have historically shown little regard for the unpredictable consequences of violating international law.

For example, Iraq, the Chagos Islands, the Brexit trade deal concerning customs checks in Northern Ireland, etc.

I suppose it's all really just one big political matter: do they want to chance it? Probably not, but they could, legally. We just haven't had the government who's willing to do that yet, but given the current government's willingness to flout international law, prudence seems like it might have vanished some time ago...

[d1sxeyes]

> In this case, such a law in Scotland could potentially breach Article 3 of the Convention which prohibits inhuman or degrading punishment. The British Parliament can simply choose to ignore it, but the Scottish Parliament can't (unless the British Parliament chose to give it such powers).

Well, if Westminster choose to ignore the convention, I don't see why Holyrood would not choose to ignore Westminster?

This whole politics thing only works if we DON'T ignore stuff we all signed.

[Veen]

Holyrood derives its power from Westminster and Westminster can remove it. The UK Parliament is still supreme, but it refrains from making laws in areas that are devolved to local Parliaments (the Sewell convention). It could overturn the Scotland Act that created the Scottish Parliament. In theory, Scotland could ignore Parliament, but that would be akin to unilaterally declaring independence, which is unlikely to go well.

The ECHR has no such powers over signatories.

[d1sxeyes]

I think this is the point. All of these arrangements are ultimately by consent. Holyrood agrees to recognise Westminster's power, just as the UK agrees to recognise the ECHR.

This idea of 'power' is a complicated one. What 'power' does England have over Scotland other than the power that Scotland has agreed to accept (see Northern Ireland for what happens when one of the devolved nations is conflicted over whether to accept that power)? What 'power' does the ECHR have over any of its signatories other than that which they've chosen to accept?

There's a well-written and detailed exploration of the negative consequences of withdrawing from the ECHR here, and what is power except the ability to impose negative consequences for not following instructions?

https://verfassungsblog.de/uks-potential-withdrawal-european...

[matthewheath]

> what is power except the ability to impose negative consequences for not following instructions?

Yes, I think power is exactly this.

> What 'power' does England have over Scotland other than the power that Scotland has agreed to accept

A monopoly on violence to enforce its territorial integrity as the United Kingdom. Withdrawing from international treaties is generally accepted to be within a state's general powers. Seceding from an existing state? Generally recognised by the current international order as unlawful and solely a matter for the state to resolve internally.

Would there be international condemnation if Scotland seceded and England tried to take it back by force? Yes, but doing so would embolden existing secessionist movements in, e.g. Spain or the United States, so those states (plus the ones who promote non-interference in domestic affairs) aren't going to intervene in any meaningful sense.

I think power must go beyond consent and incorporate the expectations and realities of the nature of sovereign state power on the international stage. The UK has the right to insure its territorial integrity, while the principle of self-determination is limited within that framework.