Member States shall take all necessary measures to ensure that:

(a) any laws, regulations and administrative provisions contrary to the principle of equal treatment are abolished;

(b) provisions contrary to the principle of equal treatment in individual or collective contracts or agreements, internal rules of undertakings or rules governing the independent occupations and professions and workers' and employers' organisations or any other arrangements shall be, or may be, declared null and void or are amended;

(c) occupational social security schemes containing such provisions may not be approved or extended by administrative measures.