In a new blog for the Judicial Power Project, Mikolaj Barczentewicz, a Lecturer in Law at the University of Oxford’s Jesus College, looks at the relationship between national law and EU law. Barczentewicz writes that UK domestic courts have never accepted that EU law has direct force in the UK outside of the scope of incorporation by the European Communities Act 1972, but that this is clearly not what the European Court of Justice believes. He explains how it is up to UK courts to decide whether the European Court of Justice has overstepped the limits of its jurisdiction. Referring to the recent controversy over changes to the Ministerial code – which removed the explicit requirement for Ministers to comply with international law – Barczentewicz argues that British judges ultimately have a duty to disregard international law when it conflicts with domestic law.


The debate over removing the explicit reference to an overarching duty to comply with international law from the Ministerial Code is of direct relevance to the question of the relationship between domestic law and EU law. The EU’s supreme court, the Court of Justice in Luxembourg (‘CJEU’), has a somewhat imperialistic vision of its own power and of the relationship between EU law and national law. According to this vision, the CJEU is the sole arbiter of the limits of its own authority, as well as of the limits of the EU’s competences. However, the UK Supreme Court has recently suggested in HS2 and in Pham that this vision is at odds with UK law. From the perspective of UK law, it is UK law that has the final say on the nature and scope of both the legal effect of EU law and of the CJEU’s jurisprudence.

If you ask in Luxembourg who decides the limits of Luxembourg’s power, the answer is simple: Luxembourg. In a long string of cases dating back to the early 1960s the CJEU has asserted that EU law has unconditional supremacy over domestic law, within the limits of the Treaties. The CJEU has also asserted that it holds the ultimate power to determine the limits of the Treaties. Of course, according to the CJEU, EU law also just means what the CJEU says it means – no one is allowed to question that. In particular, domestic courts are expected to take everything the CJEU says at face value and give full effect to it in their judgments, no questions asked.

Nevertheless, national courts have been asking questions. Notably, the Federal Constitutional Court of Germany confirmed on many occasions that the CJEU’s vision of EU supremacy is misconceived, at least from the German perspective. EU law has legal effect in Germany only because and to the extent that the German Constitution allows it. This does not mean that the legal effect is insignificant, but only that it is not unlimited and that it is ultimately for national authorities to decide where the limits lie.

Has the time come for the UK courts to put the Luxembourg Court in its place? It seems so. Since the famous 1990 judgment of the House of Lords in Factortame (No 2), UK courts have been ensuring the effectiveness of EU law and of the Luxembourg jurisprudence, even to the extent of ordering disapplication of an Act of Parliament. For a recent example, see the Davis case. Arguably, the courts have correctly construed what Parliament expected them to do when enacting the European Communities Act 1972 (‘ECA’). The ECA provides for EU law to have very far-reaching effects in the UK. This was a legislative choice and the courts would have been derelict in their duty not to follow it.

Importantly, UK domestic courts have never accepted that EU law has any direct force in the UK outside of the scope of incorporation by the ECA 1972. Yet this is emphatically not what the CJEU has in mind when it refers to the supremacy of EU law. EU supremacy is supposed to be unconditional, without regard to the limits of national incorporating measures like the ECA 1972. In practical terms, to make EU supremacy a reality, the CJEU needs national courts to be its accomplices in disregarding the national limits on the effectiveness of EU law. Following cases such as HS2 and Pham we now have good reason to think that UK courts are not willing to join the conspiracy.

In last year’s HS2 judgment, the Supreme Court asserted clearly that the effectiveness of EU law in the UK is limited by the scope of the legislative choice made by Parliament when enacting the ECA 1972 (a proposition confirmed in any event by s 18 of the European Union Act 2011). Factortame did not change that. Lord Neuberger, the President of the Supreme Court, and Lord Mance even went so far as to suggest that Parliament, while enacting the ECA 1972, did not intend to abrogate fundamental constitutional principles of the UK. The consequence is that if EU law, otherwise incorporated by the ECA, conflicts with a constitutional principle, not abrogated by the ECA, the UK constitutional principle wins and EU law has no effect, irrespective of what the Luxembourg Court says.

The position taken by their Lordships is sound. Parliament should be presumed to know that some parts of the law are of fundamental importance and to take that into account in its legislative choice. What follows is that the courts ought only to take Parliament to have intended to abrogate a constitutional principle, whatever its source, when such a conclusion follows from express words or, short of that, is otherwise inescapable (see Laws LJ in Thoburn and Lord Hoffman in Simms).

The case before the Supreme Court did not require the Justices to take a stronger stance, which partly explains their restraint. However, it is to be hoped that if and when necessary, the judges will give effect to the legislative choice of Parliament in the ECA 1972, properly construed, and not to the dreams of the Luxembourg court.

Lord Mance’s speech in Pham from March 2015 suggests that this will be so. In Pham he expressly reaffirmed the HS2 position that international law, including EU law, may only have direct effect in the UK when incorporated by an Act of Parliament. It is true that Parliament was very generous in its recognition of EU law in the ECA, but it does not follow – pace Luxembourg – that there are no domestic limits . The chief limitation is the scope of the EU Treaties. What bears emphasis is that the EU has no ‘inherent’ powers – it does not exist beyond the scope of the Treaties that brought it into being, all of its powers are borrowed (conferred). The crucial passage from Lord Mance’s speech should be quoted verbatim:

A domestic court faces a particular dilemma if, in the face of the clear language of a Treaty and of associated declarations and decisions … the Court of Justice reaches a decision which oversteps jurisdictional limits which Member States have clearly set at the European Treaty level and which are reflected domestically in their constitutional arrangements. But, unless the Court of Justice has had conferred upon it under domestic law unlimited as well as unappealable power to determine and expand the scope of European law, irrespective of what the Member States clearly agreed, a domestic court must ultimately decide for itself what is consistent with its own domestic constitutional arrangements, including in the case of the 1972 Act what jurisdictional limits exist under the European Treaties and upon the competence conferred on European institutions including the Court of Justice. 


What is undeniable is that the CJEU has not had ‘conferred upon it under domestic law unlimited as well as unappealable power.’ Hence, it is up to UK courts to decide whether the Luxembourg Court has overstepped the limits of its jurisdiction. And when a domestic court finds that this is what happened, then it has a duty to recognize such judgment of the CJEU for what it is: a nullity (to the extent it is outside of the limits of the CJEU’s power).

Lord Mance adds that such situations are likely to be very rare and he may very well be right. However, the principle is important and the current wording of the Ministerial Code correctly reflects it: it is Parliament and domestic law that decides and it is for domestic courts to police the limits of recognition of international law. UK judges not only lack a duty to follow international law outside of the scope of incorporation in UK law, they positively have a duty to disregard international law when it conflicts with domestic law, properly construed.

Mikolaj Barczentewicz
Lecturer in Law, Jesus College
University of Oxford