Explanatory Notes

The general principles of EU law

50 The general principles are the fundamental legal principles governing the way in which the EU operates. They are part of the EU law with which the EU institutions and member states are bound to comply. General principles are applied by the CJEU and domestic courts when determining the lawfulness of legislative and administrative measures within the scope of EU law, and are also an aid to interpretation of EU law. Examples of general principles include proportionality1, non-retroactivity (i.e. that the retroactive effect of EU law is, in principle, prohibited), fundamental rights2 and equivalence3 and effectiveness.4

51 UK laws that are within the scope of EU law and EU legislation (such as directives) that do not comply with the general principles can be challenged and disapplied. Administrative actions taken under EU law must also comply with the general principles.

1 Whether the proposed action exceeds what is appropriate and necessary to achieve its objective. See for example cases ABNA C-453/03, C-11/04, C-12/04 and C-194/04 EU:C:2005:741, paragraphs 76-85.

2 See for example Hauer case 44/79, EU:C:1979:290 paragraph 15

3 Under this principle, Union law based claims must be treated in an equivalent way to claims based solely on domestic law. They cannot be treated less favourably. This principle is essentially a prohibition against discrimination (see Starjakob, C-417/13, EU:C:2015:38, paragraphs 70 to 75, the Court confirmed that the principle of equivalence is not relevant to a situation which concerns only Union law based claims.

4 Under the principle of effectiveness, it must be neither practically impossible nor excessively difficult to enforce a Union law based claim. See Van Schijndel, Cases C-430/93 and C-431/93, EU:C:1995:441, paragraph 19.


Prepared 13th July 2017