"(c) where a women is employed on work which, not being work in relation to which paragraph (a) or (b) above applies, is, in terms of the demands made in her of equal value to that of a man in the same employment- (i) if (apart from the equality clause) any term of the woman's contract is or becomes less favourable to the woman than a term of a similar kind in the contract under which that man is employed, that term of the woman's contract shall be treated as so modified as not to be less favourable, and
"(3) An equality clause shall not operate in relation to a variation between the woman's contract and the man's contract if the employer proves that the variation is genuinely due to a material factor which is not the difference of sex ..."
"(1) Where on a complaint or reference made to an industrial tribunal under section 2 above, a dispute arises as to whether any work is of equal value as mentioned in section 1(2)(c) above the tribunal may either- (a) proceed to determine that question; or (b) unless it is satisfied that there are no reasonable grounds for determining that the work is of equal value as so mentioned, require a member of the panel of independent experts to prepare a report with respect to that question;
"(2) In proceedings to which the rules in Schedule 1 apply and which involve an equal value claim, the rules in Schedule 2 (including rule 8A) shall apply in place of rules 4, 9, 10, 12, 13 and 20 in Schedule 1."
"9.-(1) The tribunal shall, so far as it appears to it appropriate, seek to avoid formality in its proceedings and shall not be bound by any enactment or rule of law relating to the admissibility of evidence in proceedings before the courts of law. The tribunal shall make such enquiries of person appearing before it and witnesses as it considers appropriate and, subject to paragraphs (2A), (2B), (2C), (2D) and (2E), shall otherwise conduct the hearing in such manner as it considers most suitable to the clarification of the issues before it and generally to the just handling of the proceedings."
"(2E) A tribunal may, on the application of a party, if in the circumstances of the case, having regard to the considerations expressed in paragraph (1), it considers that it is appropriate so to proceed, hear evidence upon and permit the parties to address it upon the issue contained in subsection (3) of section 1 of the Equal Pay Act ... before determining whether to require an expert to prepare a report under rule 8A."
"Both parties have gone to considerable expense in preparing their own expert's reports and arranging for these experts to attend the Tribunal for the purposes of giving evidence. The procedure available under Rule 9(2E) takes place before the Tribunal determines whether to require an expert or to prepare a report under Rule 8A, in other words before the expense of that has been incurred."
"The situation here is quite different because although there is no independent expert's report both parties have already incurred considerable expense in having their own report.