The privilege row between Harbottle and News Corp reveals the ties that bind advisers

Given its media credentials, it's not unfitting that Harbottle & Lewis' battle to defend its role in the phone-hacking saga against criticism by former client News International is being played out so prominently in the public eye. Harbottle's statement last Tuesday (19 July) that it had asked for and been refused permission to waive client confidentiality obligations and defend itself publicly against mounting criticism by both its former clients and politicians was understandable.

After all, in a story that relates to an opinion the firm gave in 2007 that there was no reasonable evidence that phone-hacking extended beyond one News of the World journalist based on evidence it had reviewed, criticism of the firm was escalating by the day. Why shouldn't Harbottle, then, be allowed to answer as News Corporation seemingly tried to pass the buck to its subsidiary's former lawyers?

On the other hand, legal professional privilege is at the very core of all lawyer/client relationships, so why should a law firm be able to break it just because it happens to have been criticised in one of the largest-ever media scandals? News International's subsequent decision to grant Harbottle permission to answer questions from police and Parliamentary select committees appears to have resolved the matter, but the episode is a rare exposure of the ambiguities and tensions inherent in privilege.

Unless a client is willing to waive confidentiality obligations, there is nothing a law firm can do to reverse its decision – regardless of any reputational damage caused as a consequence. This means that in the absence of a waiver, other than in exceptional circumstances such as where clients have deliberately used their lawyers to cover up a crime, firms may have to go as far as launching defamation proceedings to clear their name – a tactic no 'brand' law firm would want to be seen pursuing.

Views often vary, as well, as to when a client has effectively waived privilege by publicly discussing advice. However, while sympathy in legal circles for Harbottle's position is considerable, not everyone agrees the firm should have taken the route it did.

As partnership specialist Roderick l'Anson Banks comments: "To have a firm seeking to defend itself on the public stage is unthinkable. One may have sympathies in terms of what was said, but client confidentiality is absolute and public criticism is not an excuse for ignoring it. Only the client has the right to waive confidentiality and it isn't right for lawyers to get involved in a tit-for-tat argument – professionally, they must step back. The best thing they could do is keep their heads down and try to minimise any client damage."

Yet the reality is that few, if any, law firms have been caught up in a public controversy of the scale and intensity surrounding the alleged phone-hacking at News International. However this plays out, it's clear that a lot of reputational damage has already been done, with News Corp chief executive Rupert Murdoch publicly alleging that Harbottle made a "major mistake" in a newspaper interview this month and former director of public prosecutions Lord Ken Macdonald QC stating in Parliament that some evidence seen by Harbottle showed evidence of criminal activity.

When Harbottle gives its Parliamentary evidence in October, there will be much focus on how narrow the brief was that the firm was given – itself raising age-old questions about the use that clients can put tightly-defined legal opinions to and how that reflects on a lawyer. But transparency is a strategy with risks for Harbottle, as underlined by last week's news that a preliminary investigation into the role of solicitors in phone-hacking has been launched by the Solicitors Regulation Authority.

As one professional negligence partner comments: "It's a reputational nightmare, but this is a high risk strategy that seems more of a PR strategy than a legal strategy. Why should any client waive confidentiality so that a law firm can say something bad about them?"