First, I was not of the view that the Respondent’s potential liability to maintain the Child ought to have been raised during the divorce proceedings between the Applicant and the Ex-Husband. For the extended doctrine of res judicata to apply, the Respondent must show that the connection between the issue of maintenance in the divorce proceedings and the present proceedings rendered it unjust or oppressive for OAG 154 to be brought. This might be, for example, where the same defendant had been sued by two different plaintiffs on identical issues which had already been determined in an earlier action (see Andy Lim at [43]; Ong Han Nam at [73]), or where the same plaintiff sued different parties where the defendants had a “privity of interests”, ie, such a close or special relationship or commonality of interest that the plaintiff ought to have brought a claim against all the defendants in one and the same action (see Andy Lim at [43], citing Gleeson v J Wippell & Co Ltd [1977] 1 WLR 510 at 515). When Sir Robert Megarry VC considered the phrase “privity of interest”, he regarded this to mean that there was a sufficient degree of identity between the prior defendant and the new defendant, having due regard to the subject matter of the dispute, that it would be just to hold that the decision to which one was party should be binding in proceedings to which the other is party (Gleeson v J Wippell & Co Ltd [1977] 1 WLR 510 at 515).