(1) If and so far as the terms of a contract of employment do not include (expressly or by reference to a collective agreement or otherwise) a non-discriminatory equality clause, they shall be taken to include one.

(2) A non-discriminatory equality clause is a provision relating to the terms of a contract of employment, other than a term relating to remuneration or pension rights, which has the effect that if -

(a) C is employed in circumstances where the work done by C is not materially different from that done by D in the same employment, and

(b) at any time C's contract of employment would (but for the non-discriminatory equality clause) -

(i) contain a term which is or becomes less favourable to C than a term of a similar kind in D's contract of employment, or

(ii) not include a term corresponding to a term in D's contract of employment which benefits D,

then the terms of C's contract of employment shall be treated as modified so that the term in question is not less favourable to C or, as the case may be, so that they include a similar term benefiting C.