primary sources of EU law
includes 'founding treaties' that created the EU - Treaty of Rome 1957
'accession treaties' that enlarge the EU to include new member states
'amending treaties' that extend the scope of the EU - Lisbon treaty 2007
by signing a treaty member states agree to create new laws, which meet the principles and aims laid down in treaties
divided into articles which are directly applicable, if contain rights on which individuals can rely, they have both vertical and horizontal direct effect - Van Gend en Loos, Marshall v Southampton