<P> In its final report (1980), the Metrication Board wrote "Today metric units are used in many important areas of British life--including education; agriculture; construction; industrial materials; much of manufacturing; the wholesaling of petrol, milk, cheese and textiles; fatstock markets and many port fish auctions, nearly all the principal prepacked foods; posts and telecommunications: most freight and customs tariffs; all new and revised Ordnance Survey maps; and athletics . Nevertheless, taken as a whole, Britain is far from being wholly metric ." The report major identified areas that had not yet been metricated as being the retail petrol trade (metricated in 1984), retail sale of loose goods (metricated in 2000) and roads signs (not metricated). </P> <P> The report did not address issues related to the media such as news reports and advertising . </P> <P> The regulations that came into force on 1 January 2000 regarding the sale of loose goods effectively made it mandatory to use metric units in the retail industry for most products though supplementary indicators using certain imperial units were still permitted under United Kingdom law . Various price - marking orders prescribed the sizes in which products could be marketed . Some of these restrictions, such as wine being sold in 750 ml bottles, were derived from EU directives, while others, such as the production of bread in 400 g or 800 g loaves, were applicable to the United Kingdom only . The principle of the Internal Market, backed up by a judgment of the European Court of Justice, required that any product that was legally produced anywhere in the European Union could, in most cases, be sold anywhere in the EU . Thus a 500 g packet of rye bread, legally manufactured in Germany, could be sold in the United Kingdom even though it was not lawful under British law for a British baker to produce an identical 500 g packet of bread . </P> <P> A consultation by the EU aimed at bypassing this impasse was launched in 2004 . The outcome was Directive 2007 / 45 / EC which deregulated prescribed packaging of most products, leaving only wines and liqueurs subject to prescribed EU - wide pre-packaging legislation . While this effectively undid much of the work done by the Metrication Board by deregulating prescribed sizing for over 40 products, the law relating to labelling of products has remained unchanged . </P>

When did the uk change from imperial to metric