4.10.1 A party to a proceeding may at any time make to any other party to the proceeding a written offer that—
(a) is expressly stated to be without prejudice except as to costs; and
(b) relates to an issue in the proceeding.
4.10.2 The fact that the offer has been made must not be communicated to the court until the question of costs is to be decided.
Compare: SR 1992/109 r 47G