1.
—(1) Where in any action a defendantwho has entered an appearance —
(a)
claims against a person not already a party to the action any contribution or indemnity;
(b)
claims against such a person any relief or remedy relating to or connected with the original subject-matter of the action and substantially the same as some relief or remedy claimed by the plaintiff; or
(c)
requires that any question or issue relating to or connected with the original subject-matter of the action should be determined not only as between the plaintiff and the defendant but also as between either or both of them and a person not already a party to the action,
then, subject to paragraph (2), the defendant may issue a notice in Form 16 or 17, whichever is appropriate (referred to in this Order as a third party notice), containing a statement of the nature of the claim made against him and, as the case may be, either of the nature and grounds of the claim made by him or of the question or issue required to be determined.
(2) A defendant to an action may not issue a third party notice without the leave of the Court unless the action was begun by writ and he issues the notice before serving his defence on the plaintiff.
(3) Where a third party notice is served on the person against whom it is issued, he shall as from the time of service be a party to the action (referred to in this Order as a third party) with the same rights in respect of his defence against any claim made against him in the notice and otherwise as if he had been duly sued in the ordinary way by the defendant by whom the notice is issued.