In general, the public interest in the proper administration of justice requires that people called as witnesses before courts must answer all questions put to them, on pain of being held in contempt of court. However, the common law has recognised some exceptions, such as the privilege of the police to be able to refuse to identify their sources, or that of lawyers or doctors to refuse to answer questions about conversations with clients. In such cases, there is a countervailing public interest in favour of encouraging full disclosure between the parties to the relationship. The categories of relationship which attract such privilege are controversial; it has been claimed to cover the relationship between journalists and their sources, or that between priests and their penitents – some jurisdictions recognise these extensions, some don’t (in Ireland – exceptionally in both cases – the former is an open question, and the latter is recognised).
In the way of these things, I have come across two interesting contributions to the deabte about the nature of such evidential privileges. In the first, In re McE  UKHL 15 (11 March 2009) (also here) the House of Lords (Lord Hope, Baroness Hale, Lord Carswell and Lord Neuberger for the majority; Lord Phillips dissenting) held that that the the Regulation of Investigatory Powers Act 2000 (RIPA) allows for covert surveillance of communications between lawyers and their clients, even where these are covered by legal professional privilege. The case has significant implications for the malign impact of RIPA upon privacy rights, but it also contains some important discussions of the nature of legal professional privilege.
First, Lord Hope and Baroness Hale (in the majority) treated legal professional privilege as a procedural and evidential matter, whereas Lord Phillips (dissenting) thought that it had went further and extended into a substantive fundamental right. Lord Nueberger (also in the majority) referred to the very closely connected “right of a person to consult a lawyer in private, and the right to legal professional privilege in connection with communications with one’s lawyer”. Lord Carswell (delivering the main speech for the majority) acknowledged that legal professional privilege is now being spoken of in terms of substantive rights, but did not feel it necessary to decide whether the evolution postulated by Lord Phillips (and, it seems, assumed by Lord Nueberger) had in fact taken place. This distinction matters: if legal professional privilege is seen in procedural evidential terms, it is easily displaced by a countervailing public interest; on the other hand, if it is seen as a substantive and fundamental human right, it is much harder to displace, except by express legislative enactment. In other words, the status, strength and limits of legal professional privilege as a privilege or a right are still being tested.
Second, there was much discussion of the principle that there is no privilege in iniquity, so that communications between a lawyer and client that are in furtherance of crime or fraud are not protected by legal professional privilege; but all were agreed that this applied to the privilege whether it is a procedural and evidential issue, or a matter of substantive right. In the Yale Law Journal Pocket Part (an online companion to the Yale Law Journal) Colin Miller (profile | blog) has just published a piece on evidential privileges which argues that all such privileges must serve competing interests which are not undercut by such crime-fraud exceptions; see Colin Miller “A Public Privilege” 118 Yale LJ Pocket Part 166 (2009) (mp3 podcast). On the nature of legal professional privilege (or, in US terms, attorney-client privilege) he says
… no privilege is an island, entire of itself, and, as the Supreme Court announced in Jaffee v. Redmond, all privileges must further both private interests and public ends. The attorney-client privilege is no exception. As the Supreme Court articulated in Upjohn Co. v. United States, the purpose of the privilege “is to encourage full and frank communication between attorneys and their clients and thereby promote broader public interests in the observance of law and administration of justice.” Indeed, the core premise of the privilege is “that sound legal advice or advocacy serves public ends.”
He then argues that these public ends are bolstered by the crime-fraud exception. The aim of the piece is to reason by analogy from that conclusion to the context of a statutory journalist source privilege (or, in US terms, “shield law”) to support the argument that the latter statutory privilege should also be subject to the crime-fraud exception, despite a recent state court decision to the contrary.
From an Irish perspective, we must await the decision of the Supreme Court on the existence (and, if it exists, the extent) of a journalists source privilege, so we must put that aspect of Miller’s analysis aside for a while. Similarly, not being blessed or cursed (yet?) with an equivalent of RIPA, we can also (and quite happily) put that aspect of the decision of the House of Lords in In re McE to one side. What remains in both cases is a revealing discussion of the nature and limits of legal professional privilege. For my own part, I would be slow to make too much of the analogy from one form of evidential privilege to another. If legal professional privilege is evolving into a substantive right, then its contours will be informed by considerations that do not necessarily apply in other contexts – in particular, arguments that it can be displaced simply by countervailing public interests (which might be sufficient in the context of other privileges) will be much harder to sustain. Again, it is perfectly plausible that the rationale in favour of the crime-fraud exception could be much stronger in the context of one privilege than of another.