The law is more than what is written in an act of parliament. Sure, parliament can pass a law that grants anybody any powers – but parliament also passed the Data Protection Act 2018, bringing the GDPR into domestic law. Treaty obligations, legal principles, and the interaction of different overlapping laws can all result in inconsistencies.
The UK government has passed quite a few laws and government departments have taken their own interpretations of these – for instance, the home office has been using tax filing corrections (fairly routine practice in the UK) as evidence of dishonesty – in some cases the amounts owed didn't change – and using these to write the your-immigration-status-has-changed-go-home-before-we-deport-you letter. [0]
A lot of interpretations of legislation fall under the "there is no case law – it is probably unlawful but plenty of others are doing it and the worst that can happen is..." category.
The UK government has passed quite a few laws and government departments have taken their own interpretations of these – for instance, the home office has been using tax filing corrections (fairly routine practice in the UK) as evidence of dishonesty – in some cases the amounts owed didn't change – and using these to write the your-immigration-status-has-changed-go-home-before-we-deport-you letter. [0]
A lot of interpretations of legislation fall under the "there is no case law – it is probably unlawful but plenty of others are doing it and the worst that can happen is..." category.
[0] https://www.theguardian.com/uk-news/2018/nov/23/home-office-...