International courts - especially US ones - have de facto overrides on UK sovereignty in many domains.

If Royal Mail put the asset into a US subsidiary then US courts must protect it.

Regardless of what the UK domestic authorities say, very few entities would be willing to risk violating US copyright laws.

They can try to protect it but anything inside the UK is subject to UK law and no other law. As I said, there may be practical concerns (read, consequences) for a course of action but this is separate to the domain of law.

Inside the UK, if a law explicitly counteracts, say, an international treaty, the British courts MUST find in favour of British law.

> anything inside the UK is subject to UK law and no other law

This is true in theory but not in practice. If you’ve been sanctioned by the US then you won’t by able to get a bank account in the UK. Even if you’ve not violated any UK law.

The Americans can give a British bank an ultimatum between dealing in US dollars and dealing with a particular individual. Every bank will always choose the former.

Similarly anything with US assets is subject to the US court system any its interpretation of copyright. Naturally this means US companies need to obey its rules.

But also given the reach of copyright law, so do foreign companies that interact with US ones. Visa, Mastercard, Google, FedEx, and Stripe can’t do business with someone who openly violates US copyright.

So perhaps a local council using self hosted services could use nationalised data but that’s about it.

The examples you gave are nothing to do with Parliament creating a law, they’re all based on individual actions.

And in any case, my disclaimer already covered the bases you’re discussing:

> If it has knock-on impacts in other areas, it's hard to say, but that's separate to the law.

I’d hoped it was clear that I was referring to UK law but perhaps not.

It’s perhaps a difference in what we consider to be UK law. A difference between laws authored in the UK and laws enforced in the UK.

Parliament might be the de jure authority on UK law, but in practice many other bodies have the de facto power to write laws that apply in the UK.

You’re overthinking the issue. The laws not authored but enforced in the U.K. are done so with the express authority of Parliament. Treaty ratification is literally “passing an Act of Parliament that implements the treaty in U.K. law.” Parliament can also delegate legislation authority to other bodies. It can also revoke that authority (within the U.K.) either in part or in full.

This has actually happened on multiple occasions: Brexit being one that removed European institutions’ right to set rules that the U.K. must comply with. It’s also an example of where this isn’t free: the government agreed to a bunch of rules right back because cutting ourselves off from Europe would have obliterated the economy.

Article 1 of Protocol 1 of the ECHR covers exactly this, so the Supreme Court (and ECtHR if it came to that) would probably find in favour of Royal Mail if this were to be done without compensation.

The court would make a "declaration of incompatibility" with the ECHR which leaves it up to Parliament to change the law.

https://en.wikipedia.org/wiki/Declaration_of_incompatibility

If it were done by an Act of Parliament, no they wouldn’t. If that Act explicitly overrides external concerns, the Supreme Court must find in favour of the Act and the ECHR would have to find against it, which the UK Parliament is free to ignore, if it so chooses.

As I point out, this isn’t “free” because it can invite consequences from other parties. But that’s a different domain to law.