Yes, Parliament has absolute and unlimited power (except binding future Parliaments, and maybe arguably some matters relating to Scotland): https://en.wikipedia.org/wiki/Parliamentary_sovereignty_in_t...

(not a lawyer)

Not a Brit, not a lawyer...

The promise could be re-interpreted in some funny ways. For example, Count Binface didn't specify when nationalizing Adele would occur.

They could create another[0] special case in UK copyright law with a minor twist: Instead of eventually entering the public domain, the copyright of Adele's works would transfer to the UK government which would donate any proceeds to a charity that builds affordable homes.

Silly, but it'd mean two promises kept.

[0] https://neverlandofficial.com/discover/peter-pan-copyright/

Parliament theoretically has unlimited power, practically I think this stops short of reintroducing actual slavery. Lawyers would be busy arguing in international courts; but hopefully 50℅ of the electorate might actually bother to vote.

A simple bill of attainder would do it, but she'd have recourse to the ECHR to appeal it, which would in practice bind the UK. If we thought she wasn't going to be chill with it, we'd first need to withdraw from the ECHR. As it happens, withdrawing from the the ECHR is a prime Farage objective.

Lawyer here.[0] Definitely possible.[1]

[0] not a lawyer [1] what does “nationalise” even mean?