"Each Member State shall during the first stage ensure and subsequently maintain the application of the principle that men and women should receive equal pay for equal work."
"(1) A person discriminates against a woman in any circumstances relevant for the purposes of this Act if - (a) on the ground of her sex he treats her less favourably than he treats or would treat a man, or (b) he applies to her a requirement or condition which he applies or would apply equally to a man but - (i) which is such that the proportion of women who can comply with it is considerably smaller than the proportion of men who can comply with it, and
"(2) It is unlawful for a person, in the case of a woman employed by him at an establishment in Great Britain, to discriminate against her - (a) ... (b) by dismissing her, or subjecting her to any other detriment."
"In cases in which it is established that a group of women is being disadvantaged in comparison with a group of male workers, (doing work which is the same or of equal value in the same plant or undertaking) no additional factor, whereby unequal treatment is applied, need be required."
"Attention should be directed less to the existence of a requirement or a hurdle by means of which women suffer a disadvantage, and more to the discriminatory result. Against that background, it is part of the nature of indirect discrimination that a comparison between the sexual groups is carried out in order to determine the alleged discriminatory effect."