3.—(1) In article 5(2)—
(a)for “paragraph (1)” substitute “paragraphs (1) and (2A)”;
(b)after “in this article” insert “(“a relevant contract”)”.
(2) After article 5(2) insert—
“(2A) Where any relevant contract provides for payment for a unit of work to be based on an average value of units of work previously carried out, paragraph (2) shall not apply but the rates applied in calculating that average value shall be no higher than rates 2.5% greater than the rates in the following paragraphs.”.