[dghf]

There is no such thing as an illegal Act of Parliament in the UK. Parliament has unfettered power to pass whatever laws it sees fit, regardless of existing laws, treaties, or whatever.

(At least, that's the standard interpretation, though some authorities have suggested it's not quite as simple as that: see https://en.wikipedia.org/wiki/Parliamentary_sovereignty_in_t... for details.)

[vdqtp3]

To take this to an extreme, are you saying that under UK law, it would be legal for Parliament to legalize slavery or permit other activities that would unconscionable and illegal without such action?

[bananapub]

> To take this to an extreme, are you saying that under UK law, it would be legal for Parliament to legalize slavery or permit other activities that would unconscionable and illegal without such action?

definitely. why is this surprising? countries permit all sorts of unconscionable things (the US had slavery and only banned it "except as a punishment for crime", literally has the death penalty right now) and by definition legislatures turn things from "illegal" to "legal" and vice versa constantly. the US could re-legalise slavery via a constitutional amendment any time it wanted, Ireland could ban divorce again, Australia could un-repeal Section 127, etc etc.

the only difference in the UK is that there's no "basic law" / "constitution" that's harder to change than regular laws.

[polymatter]

Yes to my understanding. Parliament makes the laws. No court can override Parliament. No existing law binds Parliament. The only thing stopping this is how incredibly embarrassing it would be and individual MPs might lose their next election.

https://www.parliament.uk/site-information/glossary/parliame...

[dghf]

Yes. The Supreme Court might declare such a law incompatible with the European Convention on Human Rights (incorporated into UK law under the Human Rights Act), but that does not in itself invalidate the law: it would remain the law until Parliament amended it or repealed it (if it ever did).