> Because it is not "entrenched" it can be easily changed.
Don't downvote him, he's right: we literally went round all this with the various Brexit cases. Especially "R (Miller) v Secretary of State for Exiting the European Union": https://www.supremecourt.uk/cases/docs/uksc-2016-0196-judgme...
40. "Unlike most countries, the United Kingdom does not have a constitution in
the sense of a single coherent code of fundamental law which prevails over all other sources of law"
43. "This is because Parliamentary sovereignty is a fundamental principle of the UK constitution, as was conclusively established in the statutes referred to in para 41 above. It was famously summarised by Professor Dicey as meaning that
Parliament has “the right to make or unmake any law whatsoever; and further, no
person or body is recognised by the law as having a right to override or set aside the legislation of Parliament” - op cit, p 38"
If you have a majority in Parliament - which the current government does on 43% of the vote - you can do anything. That is the long and the short of it. All the rest you might think is there - bills of attainder, retroactive legislation, any kind of rights whatsoever - can be overwritten and it is merely convention not to do so. Longstanding convention, but convention none the less. Last bill of attainder was 1820, but you could argue that the Shamina Begum case was a similar thing with extra steps.
The UK is currently subject to CJEU and ECHR external courts, but from a constitutional point of view that is "voluntary" and the government could also choose to withdraw from those just as it did from the EU.