THE CONCEPT OF WORKER (IN ARTICLE 45 TFEU)
 The notion of combating and eliminating discriminations under certain criteria against citizens of the Member States in their workplace has been adopted within the EU as well on the logic of attaining the best possible level of competitiveness. In that respect, on the basis of other provisions of the primary EU legislation, such as article 19 TFEU (former 13 TEC) and 157 TFEU (former 141 TEC), it has been normatively specified via legislative acts of the secondary sources of the EU, the most essential of which are the Council Directive 2000/34/EC of 29th June 2000 for "implementing the principle of equal treatment irrespective of racial and ethnic origin" ( OJ L180 19.07.2000 p.22.), the Council Directive 2000/78/EC of 27th November 2000 for "establishing a general framework for equal treatment in employment and occupation" ( OJ L303 02.12.2000 p.16.), the Council Directive 2002/73/EC of 23th September 2002 amending Council Directive 76/2007/EEC "on the implementation of the principal of equal treatment for men and women as regards access to employment, vocational training and promotion and working conditions"( OJ L269 05.10.2002 p.15) and the Council Directive 97/80/EC "on the burden of proof in cases of discrimination based on sex"(OJ L14 20.01.1998 p.6.). However, a basic distinction must be drawn between the above-mentioned legal framework based on articles 19 and 157 TFEU on one hand and that of article 45 §2 TFUE on the other hand in that the scope of application of the first-one can involve purely domestic workers whereas the latter cannot since it requires the existence of a cross-border element as a sine qua non condition according to settled case-law of the ECJ (C-175/78 Saunders  ECR I-637, C-180/83 Moser  ECR 2539, C-332/90 Steen  ECR I-341).
 Horspool & Humphreys "European Union Law", p.354.