“36. We can confine our consideration to the branch of LPP known as legal advice privilege, under which communications between a client and his lawyer, for the purpose of obtaining or giving legal advice (whether or not in relation to actual or contemplated litigation) are privileged from production. In other words, the client will not be required by a court to disclose them, unless one of the very limited exceptions (such as waiver) applies. We do not need to consider the similar protection also afforded, under the branch of LPP known as litigation privilege, to other documents (e.g. communications with third parties) brought into being for the purposes of litigation. 37. The development of the doctrine of legal advice privilege, and of the rationale for it, is traced in detail in the speech of Lord Taylor of Gosforth CJ in Reg v Derby Magistrates Court, Ex p. B,[1996] AC 487 , and then summarised by him as follows at p.507D: “The principle which runs through all these cases, and the many other cases which were cited, is that a man must be able to consult his lawyer in confidence, since otherwise he might hold back half the truth. The client must be sure that what he tells his lawyer in confidence will never be revealed without his consent. Legal professional privilege is thus much more than an ordinary rule of evidence, limited in its application to the facts of a particular case. It is a fundamental condition on which the administration of justice as a whole rests.” 38. Lord Taylor went on (at p. 508C) to reject a submission that, by analogy with the doctrine of public interest immunity, there might be occasions, if only by way of rare exception, in which the rule should yield to some other consideration of even greater importance: “But the drawback to that approach is that once any exception to the general rule is allowed, the client’s confidence is necessarily lost. The solicitor, instead of being able to tell his client that anything which the client might say would never in any circumstances be revealed without his consent, would have to qualify his assurance. He would have to tell the client that his confidence might be broken if in some future case the court were to hold that he no longer had “any recognisable interest” in asserting his privilege. One can see at once that the purpose of the privilege would thereby be undermined.” “The principle which runs through all these cases, and the many other cases which were cited, is that a man must be able to consult his lawyer in confidence, since otherwise he might hold back half the truth. The client must be sure that what he tells his lawyer in confidence will never be revealed without his consent. Legal professional privilege is thus much more than an ordinary rule of evidence, limited in its application to the facts of a particular case. It is a fundamental condition on which the administration of justice as a whole rests.” “But the drawback to that approach is that once any exception to the general rule is allowed, the client’s confidence is necessarily lost. The solicitor, instead of being able to tell his client that anything which the client might say would never in any circumstances be revealed without his consent, would have to qualify his assurance. He would have to tell the client that his confidence might be broken if in some future case the court were to hold that he no longer had “any recognisable interest” in asserting his privilege. One can see at once that the purpose of the privilege would thereby be undermined.”