Advice privilege and the Panama papers
The subject of legal profession privilege (LPP) is in the news at present: there is talk of its definition being reviewed in legislation going through Parliament, and its application to the Panama papers has raised question as to how it applies to the leaked documents. And yesterday (7 April 2016), the Law Society Gazette
quoted two solicitor doyens of family law - Nigel Shepherd and Tony Roe - as saying that information from the Panama leaks could be used to open up and set aside court orders on the basis of fraud (per Sharland v Sharland  UKSC 60,  2 FLR 1367
). In all of this, perhaps all lawyers need carefully to reflect on the extent to which legal professional privilege (in this case, mostly legal advice privilege (LAP)) applies, and to what extent that overrides the leaking of otherwise confidential information - which appears to be what has happened with the Panama papers.
There is a public interest in confidential information remaining private (Attorney-General v Guardian Newspapers Ltd (No 2)
 1 AC 109 [Spycatcher
case]), and this applies even more so in the case of confidential information also covered by LAP. If documents have been leaked, is anyone who comes by them entitled to rely on them in separate court proceedings? A reply to this point involves: (1) consideration of LLP generally; (2) a look at exceptions to the rules on LLP; and (3) what happens if documents are illegally disclosed (ie leaked).
Legal profession privilege; legal advice privilege
The general common law rule which applies to all court proceedings is that, subject to defined exceptions, the court must see or hear all evidence relevant to issues to decide the result. 'Privilege' is one of those exceptions. It is derived from privilegium
, the Latin for a law applied to a private individual. It is a term which is mainly applied in three totally distinct and dissimilar aspects to confidential information passed to a lawyer by a client or a potential court witness to enable the lawyer to advise and to act for the client, and it applies to the advice of the lawyer. Secondly, it applies to the right (self-incrimination privilege) which a person has in court proceedings not to give evidence which may make them liable to criminal proceedings (a right of silence). Finally, it applies jointly to parties to litigation who are willing to negotiate on terms that their admissions in negotiations remain private (without prejudice rule privilege).
LLP, or 'legal privilege' as Parliament tends to call it, is composed of two limbs: advice privilege (LAP), and litigation privilege. It is the first which is the concern here. The second applies to documents and information accumulated by lawyers, where their dominant purpose is intended litigation. Advice privilege depends on there being a confidential relationship between a client and their lawyer. The right to the privacy which results is the right of the client, not the lawyer. It is this form of privilege which is the issue in the Panama papers case: has the leaker of the information in any way permissibly breached the individual client's confidentiality, whatever one may think of that individual's tax affairs or other dealings?
The subject of advice privilege was fully considered by the Supreme Court most recently in R (Prudential plc and Anor) v Special Commissioner of Income Tax
 UKSC 1 (over the past 20 years it has been the subject of at least five more major House of Lords/Privy Council/Supreme Court judgments). Accountants who advised on tax law sought privilege for their advice. By a majority of 5:2 the Supreme Court rejected their arguments. They held that advice privilege, though defined by the common law, applied only to legal advice (in a 'relevant legal context' (Balabel v Air India
 Ch 317, Taylor J in the Court of Appeal) from lawyers, as well as patent attorneys, trade mark agents and licensed conveyancers. Any extension to this, eg to accountants' advice on tax law, surveyors on land law etc, was a matter for Parliament.
The justification for LLP is based on its importance to administration of justice: that an individual should have the right (not a 'privilege' in that sense) to 'make a clean breast' of a matter to a legal adviser (Anderson v Bank of British Columbia
(1876) 2 ChD 644 at 649, per Sir George Jessel MR). A history of the subject and a classic definition can be found in Lord Taylor CJ's speech in R v Derby Magistrates' Court, exp B
 UKHL 18. This case stressed the extents of the right and the public interest in administration of justice: that a lawyer must be able to give his client an unqualified assurance that whatever the client tells him in confidence will never be disclosed without his consent, and that this assurance is absolute subject only to the qualifications referred to below.
The Derby Magistrates
case was a remarkable case and shows the breadth of advice privilege - that it must be available to 'good guys' as well as 'bad'
). The case was described by Lord Millet in B and Others v Auckland DIstrict Law Society (New Zealand)
 UKPC 38 as follows:
' The public interest in overriding the privilege could scarcely have been higher than it was in R v Derby Magistrates' Court, exp B. B (the applicant) was charged with the murder of a young girl. He made a confession to the police, but afterwards he changed his story and said that his stepfather had killed the girl. B was tried and acquitted. The stepfather was then charged with the murder. At his committal for trial, B was called as a prosecution witness. In cross-examination he was asked by the defence about the instructions he had given his solicitors in relation to his original account of what had taken place. He declined to waive privilege. The stepfather then obtained from the stipendiary magistrate the issue of a witness summons requiring B's solicitor to produce all attendance notes and proofs of evidence disclosing B's factual instructions in defence to the charge of murder but not the advice given to him by solicitors and counsel. B applied for judicial review.'