Thoburn v Sunderland City Council (also known as the "Metric Martyrs case") is a UK constitutional and administrative law case, concerning the interaction of EU law and an Act of Parliament. It is important for its recognition of the supremacy of EU law and the basis for that recognition. Though the earlier Factortame had also referred to Parliament's voluntary acceptance of the supremacy of EU law, Thoburn put less stress on the jurisprudence of the ECJ and more on the domestic acceptance of such supremacy; Lord Justice Laws suggested there was a hierarchy of "constitutional statutes" that Parliament could only expressly repeal, and so were immune from implied repeal. Facts The Weights and Measures Act 1985 section 1 provided that both the pound and the kilogram are equally legal units of measurement in the United Kingdom. In 1994, several statutory instruments came into force bringing the United Kingdom into compliance with Directive 80/181/EEC which aimed to harmonise the use in the European Community of units of measurement. Amongst the measures enacted were the Weights and Measures Act 1985 (Metrication) (Amendment) Order 1994 and the Units of Measurement Regulations 1994. Without modifying the basic principle in Section 1 of the 1985 Act that the pound and the kilogram enjoyed parity, the Order specified that the use of the pound as a primary indicator of measurement for trade would be illegal after 1 January 2000 and would be a criminal offence under Section 8 of the 1985 Act. The 1994 Regulations permitted the continued display of imperial measures until the end of 1999 so long as the metric equivalent also appeared alongside, and at least as prominently. The Units of Measures Regulations 1994 was introduced on the basis of Sections 2(2) and (4) of the European Communities Act 1972 which authorised Ministers to pass secondary legislation to bring the UK into closer compliance with its then obligations under EU law. This is a so-called Henry VIII clause. In March 2001, Steve Thoburn, a greengrocer, was convicted at Sunderland Magistrates' Court for using weighing apparatus that did not comply with the 1985 Act. He had been warned on two occasions that his apparatus was illegal. Colin Hunt sold fruit and vegetables in Hackney, he displayed his prices by reference to imperial measures and was convicted at Thames Magistrates' Court in June 2001. Julian Harman, a greengrocer, and John Dove, a fishmonger, sold their