Sources of law are the origins from which particular positive laws derive their authority and coercive force. Such sources of law are constitutions, treaties, statutes, usages, and customs. The primary source of the European law is the Treaties, which are the basis of the European Union. The secondary sources (laws made under the terms of the treaties, especially the Treaty of Rome) comprise: • Regulations: These are binding and directly applicable (meaning that they do not have to be implemented by any national legislation) to all member states. If there is a conflict between a regulation and an existing national law, the regulation prevails. • Directives: These are requirements that member states change their national laws within a stated period of time in order to give effect to the directive in the UK. Directives can be implemented either by statute or by delegated legislation under the European Communities Act of 1972. • Decisions of the Court of Justice: These are binding on the parties to whom they are addressed, whether member states or individuals. • Recommendations and Opinions: These have no binding force, but merely state the view of the institution (such as the Commission) issuing them.