“The "without prejudice" rule is a rule governing the admissibility of evidence and is founded upon the public policy of encouraging litigants to settle their differences rather than litigate them to a finish. It is nowhere more clearly expressed than in the judgment of Oliver L.J. in Cutts v. Head[1984] Ch. 290 , 306: “That the rule rests, at least in part, upon public policy is clear from many authorities, and the convenient starting point of the inquiry is the nature of the underlying policy. It is that parties should be encouraged so far as possible to settle their disputes without resort to litigation and should not be discouraged by the knowledge that anything that is said in the course of such negotiations (and that includes, of course, as much the failure to reply to an offer as an actual reply) may be used to their prejudice in the course of the proceedings. They should, as it was expressed by Clauson J. in Scott Paper Co. v. Drayton Paper Works Ltd. (1927) 44 R.P.C. 151, 156, be encouraged fully and frankly to put their cards on the table.... The public policy justification, in truth, essentially rests on the desirability of preventing statements or offers made in the course of negotiations for settlement being brought before the court of trial as admissions on the question of liability." The rule applies to exclude all negotiations genuinely aimed at settlement whether oral or in writing from being given in evidence. A competent solicitor will always head any negotiating correspondence "without prejudice" to make clear beyond doubt that in the event of the negotiations being unsuccessful they are not to be referred to at the subsequent trial. However, the application of the rule is not dependent upon the use of the phrase "without prejudice" and if it is clear from the surrounding circumstances that the parties were seeking to compromise the action, evidence of the content of those negotiations will, as a general rule, not be admissible at the trial and cannot be used to establish an admission or partial admission. I cannot therefore agree with the Court of Appeal that the problem in the present case should be resolved by a linguistic approach to the meaning of the phrase "without prejudice." I believe that the question has to be looked at more broadly and resolved by balancing two different public interests namely the public interest in promoting settlements and the public interest in full discovery between parties to litigation.”
“24. Nevertheless there are numerous occasions on which, despite the existence of without prejudice negotiations, the without prejudice rule does not prevent the admission into evidence of what one or both of the parties said or wrote. The following are among the most important instances. (4) Apart from any concluded contract or estoppel, one party may be allowed to give evidence of what the other said or wrote in without prejudice negotiations if the exclusion of the evidence would act as a cloak for perjury, blackmail or other "unambiguous impropriety" (the expression used by Hoffmann LJ in Foster v Friedland,10 November 1992 , CAT 1052). Examples (helpfully collected in Foskett's Law & Practice of Compromise, 4th ed, para 9-32) are two first-instances decisions, Finch v Wilson (8 May 1987 ) and Hawick Jersey International v Caplan (The Times11 March 1988 ). But this court has, in Foster v Friedland and Fazil-Alizadeh v Nikbin, 1993 CAT 205, warned that the exception should be applied only in the clearest cases of abuse of a privileged occasion.” (4) Apart from any concluded contract or estoppel, one party may be allowed to give evidence of what the other said or wrote in without prejudice negotiations if the exclusion of the evidence would act as a cloak for perjury, blackmail or other "unambiguous impropriety" (the expression used by Hoffmann LJ in Foster v Friedland,10 November 1992 , CAT 1052). Examples (helpfully collected in Foskett's Law & Practice of Compromise, 4th ed, para 9-32) are two first-instances decisions, Finch v Wilson (8 May 1987 ) and Hawick Jersey International v Caplan (The Times11 March 1988 ). But this court has, in Foster v Friedland and Fazil-Alizadeh v Nikbin, 1993 CAT 205, warned that the exception should be applied only in the clearest cases of abuse of a privileged occasion.”
“64. As for the judge's second concern, I do not regard the fact that the test of good arguable case is used in other interim contexts as a sufficient reason to apply it to the issue of unambiguous impropriety when that issue arises at an interim stage of litigation. Rather, the position should be that the test remains one of unambiguous impropriety. Nothing less will do. That is a test which, deliberately, is difficult to satisfy but the fact that it arises on an interim application is no reason to dilute it. In view of the necessary limits to the conclusions which a court can reach at an interim stage, the existence of a credible dispute about what was said (or what was meant by what was said) may mean that a court cannot be satisfied that there has been an unambiguous impropriety and therefore does not admit the evidence, but that is simply the result of applying the test which has consistently and for good reason been held to apply. Plainly it would not be appropriate on an interim application to direct a trial of an issue to resolve such a dispute.”
“122. To recap, to fall within the exception, it is necessary to show that the without prejudice rule is being used to cloak wholly improper conduct and the possibility of perjury will not suffice. Conduct or statements which do not go beyond the bounds of what is to be expected in negotiation will not fall within the scope of the exception.”
“34. In Unilever plc v Procter & Gamble Co.[2000] 1 WLR 2436 Robert Walker L.J. (with whom Simon Brown L.J. and Wilson J. agreed) said that the modern cases show that the protection of admissions against interest is the most important practical effect of the rule. He continued (at p. 2448H): "But to dissect out identifiable admissions and withhold protection from the rest of without prejudice communications (except for a special reason) would not only create huge practical difficulties but would be contrary to the underlying objective of giving protection to the parties (in the words of Lord Griffiths in [Rush & Tomkins Ltd.v Greater London Council[1989] AC 1280 ,] 1300) "to speak freely about all issues in the litigation both factual and legal when seeking compromise and, for the purpose of establishing a basis of compromise, admitting certain facts." Parties cannot speak freely at a without prejudice meeting if they must constantly monitor every sentence, with lawyers or patent agents sitting at their shoulders as minders.” "But to dissect out identifiable admissions and withhold protection from the rest of without prejudice communications (except for a special reason) would not only create huge practical difficulties but would be contrary to the underlying objective of giving protection to the parties (in the words of Lord Griffiths in [Rush & Tomkins Ltd.v Greater London Council[1989] AC 1280 ,] 1300) "to speak freely about all issues in the litigation both factual and legal when seeking compromise and, for the purpose of establishing a basis of compromise, admitting certain facts." Parties cannot speak freely at a without prejudice meeting if they must constantly monitor every sentence, with lawyers or patent agents sitting at their shoulders as minders.”