Written questions to experts
159.—(1) A party may put to—
(a)an expert instructed by another party; or
(b)a single joint expert appointed under rule 160,
written questions about his report.
(2) Written questions under paragraph (1)—
(a)may be put once only;
(b)must be put within 5 days beginning with the date on which the expert’s report was served; and
(c)must be for the purpose only of clarification of the report,
unless in any case—
(i)the court gives permission;
(ii)the other party agrees; or
(iii)any practice direction provides otherwise.
(3) An expert’s answers to questions put in accordance with paragraph (1) shall be treated as part of the expert’s report.
(4) Where—
(a)a party has put a written question to an expert instructed by another party in accordance with this rule; and
(b)the expert does not answer that question,
the court may make one or both of the following orders in relation to the party who instructed the expert—
(i)that the party may not rely on the evidence of that expert; or
(ii)that the party may not recover the fees and expenses of that expert from any other party.