How has Brexit affected precedent created in European courts?

Question

I'm interested in learning how Brexit has affected precedent that existed in UK law through EU court decisions. In particular, does this remain binding?

Answer 1

In this answer, references to "Brexit" are references to the implementation date (i.e. the end of the transitional period).

All pre-Brexit EU-derived domestic legislation (e.g. legislation which implemented EU directives) and direct EU legislation (e.g. EU regulations) were kept in force in the UK as "assimilated law" by way of Section 2 and Section 3 of the European Union (Withdrawal) Act 2018.

Section 6 of the Act deals with EU case law:

• "Assimilated EU case law" is defined as any decisions made by the Court of Justice of the EU (CJEU) before Brexit and which relate to assimilated law.
• CJEU decisions made post-Brexit do not create binding precedent, but UK courts can "have regard" to them. As a principle of common law, courts can also treat post-Brexit CJEU decisions (as with any international court's decision) as persuasive.
• Subject to the exceptions below, CJEU decisions which meet the criteria for assimilated EU case law continue to have binding precedent.
• Exception 1: the UK can pass legislation which overrides any CJEU decision.
• Exception 2: The Supreme Court (in all cases) and the High Court of Justiciary (in certain circumstances) can depart from CJEU decisions in accordance with the same principles by which they can depart from their own decisions.
• Exception 3: During the transitional period, a minister could pass regulations to create other exceptions. I haven't checked if any such regulations were passed.
• Exception 4: Any conflict between a CJEU decision and the requirements of the EU-UK Withdrawal Agreement are resolved in favour of the withdrawal agreement.