"(1) A person ("the discriminator") discriminates against another person ("the person victimised") in any circumstances relevant for the purposes of any provision of this Act if he treats the person victimised less favourably than in those circumstances he treats or would treat other persons, and does so by reason that the person victimised has - (a) brought proceedings against the discriminator or any other person under this Act or theEqual Pay Act 1970 , ..."
"It is clear from that decision that a reason which is an important factor in the operative decision is quite enough, to quote Sir David Cairns [ Abernethy v. Mott, Hay and Anderson[1974] ICR 323 , 330]. In our judgment, where an industrial tribunal finds that there are mixed motives for the doing of an act, one or some but not all of which constitute unlawful discrimination, it is highly desirable for there to be an assessment of the importance from the causative point of view of the unlawful motive or motives. If the industrial tribunal finds that the unlawful motive or motives were of sufficient weight in the decision-making process to be treated as a cause, not the sole cause, but as a cause of the act thus motivated, there will be unlawful discrimination. An important factor in the decision is clearly well within that principle.
"... The difference must be "material", which I would construe as meaning "significant and relevant", and it must be between "her case and his." Consideration of a person's case must necessarily involve consideration of all the circumstances of that case. These may well go beyond what is not very happily described as "personal equation" ie, the personal qualities by way of skill, experience or training which the individual brings to the job. Some circumstances may on examination prove to be not significant or relevant, but others may do so, though not relating to the personal qualities of the employee. In particular, where there is no question of intentional sex discrimination whether direct or indirect (and there is none here) a difference which is connected with economic factors affecting the efficient carrying on of the employer's business or other activity may well be relevant."
"Alternatively, if the work is of equal value then the differential in pay arises by reason of genuine material factors which are material differences between the male's case and the applicant's and which are not based on sex. These are inter alia, the need to pay more to attract the candidate for the shipping documentation clerk's position with relevant banking experience. There were some six applicants for this position a proportion of whom were female and the salary required by all of them would have been at or around the level awarded to the successful candidate. There was no discrimination based on sex."