While Thoburn was an important case at the time it was decided, its importance for the UK law in future, when EU law will no longer apply in the UK after Brexit, will be negligible.

Thoburn v. Sunderland City Council ([2002] EWHC 195) is a constitutional case in UK law, decided by the High Court of England and Wales on 18 February 2002 on appeal from the Magistrates’ Court, which had ruled in favour of the prosecutor.

The Units of Measurement Regulations 1994 was introduced by the executive to amend the Weights and Measures Act 1985 so as no longer to permit the use of imperial units of measurement for purposes of trade other than as supplementary indications to metric units, as foreseen by the EC’s Metrication Directive (Directive 89/617/EEC). Thoburn and three others were shop owners throughout Great Britain, who were accused of committing offences against the amended Weights and Measures Act 1985 by not having their scales approved by an inspector and still weighing their products in imperial units.

The appellants argued that the amendments to the Weights and Measures Act were unlawful and invalid as, by adopting the 1985 Act, the Parliament impliedly repealed the authorisation to adopt subordinate legislation relevant to weights and measures given to the executive by the 1972 European Communities Act and that, consequently, any executive orders related to weights and measures made by the executive after 1985 would be invalid. The court was called upon to consider arguments relating to the doctrine of implied repeal and, in particular, whether the Weights and Measures Act 1985 had impliedly repealed a part of the European Communities Act 1972, to the extent that the latter empowered the provision of subordinate legislation which was inconsistent with it.

In dismissing the appeals, the Court found that there was no inconsistency between the 1972 EC Act and the amended Weights and Measures Act – that there was nothing in the 1985 Act to suggest the Parliament’s intent to repeal any part of the EC Act. The 1985 Act, as originally enacted, had not impliedly repealed any part of the 1972 Act to the extent that the latter empowered the provision of subordinate legislation which was inconsistent with it. The 1972 EC Act cannot be impliedly repealed, because it is a constitutional act, which are protected from implied repeal (and that doctrine is derived from the UK’s constitution and not EU law). The EC Act is of constitutional importance, because it created a new source of law in the UK – EC (now – EU) law.

Each specific right and obligation provided under EC law was, by virtue of the 1972 Act, incorporated into domestic law and, as long as the UK is a part of the EU, takes precedence over UK law. Anything within domestic law which was inconsistent with EC law was either abrogated or had to be modified so as to avoid inconsistency, and that was the case with the original version of the Weights and Measures Act – in 1989 it became inconsistent with EC law, so it had to be amended.

While Thoburn was an important case at the time it was decided, its importance for the UK law in future, when EU law will no longer apply in the UK after Brexit, will be negligible.