Brexit changed everything — or did it? If you're a law student in the UK, you've probably stared at a reading list wondering whether EU law is still relevant to you. The short answer: absolutely yes. Here's what you actually need to know.
What Even Is Retained EU Law?
When the UK left the EU on 31 January 2020, it didn't simply wipe the slate clean of decades of European legislation. That would have created legal chaos overnight. Instead, Parliament passed the European Union (Withdrawal) Act 2018 (EUWA 2018), which essentially "froze" EU law as it stood at the point of exit and brought it across into UK domestic law.
This frozen body of law became known as retained EU law (REUL). It includes:
EU-derived domestic legislation — UK Acts and statutory instruments that implemented EU directives
Direct EU legislation — things like EU regulations that previously applied automatically in the UK (now converted into UK law)
Rights under section 2(1) of the European Communities Act 1972 — directly effective EU law that individuals could rely on in UK courts
In practical terms, REUL covered an enormous amount: employment rights, environmental standards, consumer protection, financial services regulation, food safety rules — the list goes on. Thousands of pieces of legislation.
The Hierarchy Problem: Where Does REUL Sit?
This is where things get interesting for your exams. Under EU membership, EU law had supremacy over domestic law — that was foundational to how the EU legal order worked, established way back in Costa v ENEL [1964].
Post-Brexit, that's gone. But EUWA 2018 created its own internal hierarchy to make sense of all the retained law:
Retained EU case law sits at the top of the interpretive framework. Pre-exit CJEU (Court of Justice of the European Union) judgments were, by default, binding on UK courts in the same way that Supreme Court decisions are. However, the Supreme Court and Court of Appeal can depart from retained EU case law where they consider it right to do so — applying the same test used when departing from their own previous decisions.
Retained general principles of EU law (proportionality, legal certainty, legitimate expectations, etc.) were also preserved, though with some limits on how they can be used.
The key rule: REUL takes precedence over pre-exit domestic legislation, but post-exit UK legislation takes precedence over REUL.
The Retained EU Law (Revocation and Reform) Act 2023
Just when you thought you'd got your head around it, Parliament threw a spanner in the works.
The original plan was breathtakingly radical: a "sunset clause" that would have automatically revoked all REUL at the end of 2023 unless specifically preserved. That would have eliminated thousands of pieces of legislation overnight.
The final Retained EU Law (Revocation and Reform) Act 2023 pulled back from this cliff edge. Instead, it:
Revoked a specific listed set of REUL (around 600 pieces of legislation)
Ended the general principle that REUL takes precedence over pre-exit domestic law (from 1 January 2024)
Gave ministers broad powers to revoke, replace, or update remaining REUL more easily going forward
Removed the binding status of retained EU case law, though it remains relevant as persuasive authority
The upshot? Post-1 January 2024, what was REUL is now just ordinary UK domestic law, sitting alongside everything else, with no special status. Courts are no longer bound by pre-Brexit CJEU decisions — though they can still take them into account.
Why Does Any of This Matter for Law Students?
A few reasons this topic keeps coming up in assessments:
1. Lots of substantive law still derives from EU law. Employment law, equality law, environmental law, competition law, consumer law — significant chunks of these areas are built on EU foundations. You can't understand the current state of UK law without understanding where it came from.
2. Interpretation questions don't disappear. UK courts still have to interpret legislation that was originally drafted to implement EU directives. Do you interpret it in light of EU law principles? Do pre-Brexit CJEU cases help? These are live, contested questions in UK courts right now.
3. Northern Ireland is a different story. The Windsor Framework means EU single market rules continue to apply to Northern Ireland in important areas. If your course touches on constitutional law or devolution, this adds another layer of complexity worth knowing about.
4. It's a live area of law. Ministers continue to use their powers under the 2023 Act to reform and replace retained law. The landscape is still shifting, which means exam questions love it — and so do employers testing whether you follow legal developments.
How to Approach REUL in Your Studies
Get the timeline straight first. A lot of confusion comes from mixing up what the law said pre-2020, what it said between 2020 and 2024, and what it says now. Draw a simple timeline. Know your key dates: 31 January 2020 (withdrawal), 31 December 2020 (end of transition period), 1 January 2024 (REULA 2023 takes effect).
Focus on the interpretive questions. Examiners love asking how UK courts should approach legislation that originated in EU law. The answer isn't simple — it involves looking at the purpose of the original directive, whether pre-exit CJEU case law is persuasive, and how the 2023 Act changed the interpretive landscape.
Know your key cases. Francovich liability (state liability for failure to implement directives) is one to know well — its status in UK law is genuinely uncertain post-Brexit. Marleasing (the obligation to interpret national law in conformity with directives) raises similar questions about how much lingering interpretive obligation, if any, remains.
Don't neglect EU law itself. If you're doing any EU law module, remember that EU law continues to develop — the CJEU keeps issuing judgments, and those judgments still matter for anyone dealing with cross-border matters, trade with the EU, or advising clients operating in EU member states.
The Bottom Line
Retained EU law is one of those topics that sounds dry until you realise it affects almost every area of substantive law you're studying. Master the framework — the EUWA 2018, the hierarchy it created, and how the REULA 2023 changed things — and you'll have a significant advantage both in exams and in practice.
