The treaties, protocols, declarations and secondary legislation made under the Treaties, including most notably Regulations, Directives and Decisions. Various International agreements entered into by the Community and Union, the case law of the Court of Justice, fundamental rights from the EU Charter, the ECHR and generally from member states' constitutions and general principles of law.
2. What forms of EU secondary law exist? Are they all equally binding?Regulations, Directives and Decisions – see Article 288 TFEU. They are all equally binding but apply in different circumstances. Regulations are generally binding and thus apply to everyone, directives are usually addressed to the member states and thus obligate them and decisions are usually addressed to specific individuals.
3. How are EU laws transformed into the member state's laws?Regulations are self executing in that they are automatically binding in the member states without transformation or implementation. Directives leave the choice of form and implementation into national law up to each of the member states.
4. What is the status of protocols and declarations in the EU legal order?Protocols have the same binding status as the Treaties themselves. See Art 51 TEU. The status of Declarations is not determined by the Treaties and until there is a definitive statement by the CJEU, their actual status remains undetermined. They are certainly though highly persuasive.
5. What is the justification for the inclusion of general principles in the EU legal order?When the EC (now EU) was established, the EU legal system was to be found only in the Treaties and the limited secondary legislation that existed at the time. However, because the Treaties are largely framework Treaties, they require substantial supplement. Whilst, much of this is provided by the secondary legislation of the EU, both the secondary legislation and the founding and primary treaties' articles may need to be interpreted. There is then much scope for judicial creativity on the part of the Court of Justice. Furthermore, as with all legal systems, codified or written law cannot possibly cater for all economic and social developments that can take place and the judges must at times either adapt existing rules to fit the situation or introduce new rules to settle the matter judiciously. The Court of Justice has previously determined that the Treaty and secondary legislation must be interpreted and applied according to the scheme of the Treaty as a whole and in the light of the broad principles of the preamble and Articles 2, 3, 10, and 12 of the EC Treaty (now the preamble and Arts 3 and 4 TEU and 18 TFEU) to achieve the result required for the EU.