(1) A statement of case may be amended once, without the court's permission, at any time prior to the date fixed by the court for the first case management conference.
(2) The court may give permission to amend a statement of case at a case management conference or at any time on an application to the court.
(3) When considering an application to amend a statement of case pursuant to rule 20.1(2), the factors to which the court must have regard shall include —
(a) how promptly the applicant has applied to the court after becoming aware that the change was one which he or she wished to make;
(b) the prejudice to the applicant if the application were refused;
(c) the prejudice to the other parties if the change were permitted;
(d) whether any prejudice to any other party can be compensated by the payment of costs and or interest;
(e) whether the trial date or any likely trial date can still be met if the application is granted; and
(f) the administration of justice.
(4) A statement of case may not be amended without permission under this rule if the change is one to which any of the following applies —
(a) rule 19.4 (special provisions about adding or substituting parties after end of relevant limitation period); and
(b) rule 20.2 (changes to statement of case after end of relevant limitation period).
(5) An amended statement of case must include a certificate of truth under rule 3.11.
(6) The Chief Justice may, by practice direction, set out the procedure for —
(a) making an application to change a statement of case where the court's permission is required; and
(b) setting out changes to an amended statement of case.
• Rule 27.3(1) deals with the fixing of case management conference.