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Limited waiver, inadvertent waiver and “cherry picking”

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Recent decisions concerning the disclosure of privileged material in litigation, either deliberately or by mistake, illustrate the application of rules on inadvertent disclosure and limited waiver.  Anyone involved in disclosure, especially electronic disclosure involving many documents, should be aware of how these rules operate: (1) Abdel Hakim Belhaj (2) Fatima Boudchar (Claimants) v Director Of Public Prosecutions (Defendant) & (1) Sir Mark Allen Cmg (2) Commissioner Of Police Of The Metropolis (3) Secretary Of State For Foreign & Commonwealth Affairs (Interested Parties) (2018) (Belhaj and Boudchar v DPP) [2018] EWHC 513 (Admin), 15 March 2018 and [2018] EWHC 514 (Admin), 15 March 2018

Scope of limited waiver and consequences of inadvertent waiver

In a judicial review of the Director Of Public Prosecutions' (DPP) 2016 decision not to prosecute former senior MI6 officer, Sir Mark Allen CMG, for alleged involvement in unlawful rendition of the two claimants to Libya, the claimants sought access to certain documents that had been considered by the DPP when deciding not to prosecute.  Some of these documents had already been accidentally disclosed to the claimants. 

The privileged materials

When deciding whether or not to prosecute, the DPP had considered certain materials provided by the Foreign and Commonwealth Office (FCO).  The materials included legal advice that the FCO had received.  The provision of that legal advice to the DPP was subject to a limited waiver of privilege by the FCO.  The claimants wanted to see this legal advice. They challenged the scope of the limited waiver and argued that privilege had also been waived for the purposes of the judicial review proceedings so these documents should be made available to the claimants.

The DPP had disclosed in closed judicial review proceedings, mistakenly, it said, some of the privileged material to the claimants and sought to reassert privilege over it (on the basis that it was privileged to the FCO and was inadvertently disclosed by the DPP).  The FCO (as interested party) supported this claim to privilege.  The claimants argued that the DPP couldn’t “cherry-pick” which privileged material to disclose.

Inadvertent waiver – current law

Under CPR 31.20, if a party inadvertently allows a privileged document to be inspected, the party who has inspected the document may use it or its contents only with the permission of the court.

However, as the court noted, the case law is not entirely reflective of the terms of CPR 31.20. Rather it adopts a less favourable position towards the party who has inadvertently provided privileged material.  The starting point being that the solicitor receiving the inadvertently disclosed material owes no duty of care to the other party and is generally entitled to assume privilege has been deliberately waived. There are only limited circumstances in which the court may intervene to prevent the privileged material being used.1 Other than where disclosure was procured by fraud, this will be where there has been an obvious mistake. This is both a subjective and objective test – did the solicitor receiving the documents appreciate a mistake had been made and would it be obvious to a reasonable solicitor that a mistake had been made?

In the present case, the argument on inadvertent waiver succeeded – an obvious mistake had been made. The court found that a reasonable lawyer receiving the material that the DPP and FCO say was privileged to the FCO would be aware of both the law on inadvertent disclosure and, crucially, the very sensitive nature of the material disclosed in this closed process. In this context the court found that any reasonable lawyer receiving this information “would know or believe that the provision of material otherwise covered by [privilege] was inadvertently provided”.

Cherry-picking – requires deliberate deployment

The claimants argued that it would be unfair for the DPP to reassert privilege over the inadvertently disclosed materials since this prevented the claimants from seeing the full context of the legal advice of which those materials formed part (this is the so called ‘cherry picking’ argument). The court was clear that cherry-picking “concerns a policy or strategy by the client to use legal advice in a selective manner to obtain a forensic advantage” and in this instance there was no contention that the DPP had been seeking to tactically deploy part but not all of its legal advice. The issue of cherry-picking does not arise without “knowing, deliberate deployment resulting in partial disclosure”. There was no such intention here.

The limits of a limited waiver of privilege

The claimants challenged the scope of the FCO’s limited waiver of privilege over the privileged material. The claimants argued that the limited waiver should be extended to permit the use of the privileged documents in the judicial review proceedings.

The documents were provided by the FCO to the DPP expressly on a limited waiver basis, under the following wording:

“There are some documents provided to the investigation that may be subject to legal professional privilege. The FCO provides these papers for the sole purpose of assisting with this investigation and do not consider to have waived legal privilege for any other purpose, including any future prosecution or civil claim”.

The claimants argued that the original investigation, the DPP’s decision not to prosecute and the judicial review of that decision, were all part of one process.  It was in the interests of justice, said the claimants, for them to be able to access the legal advice that the FCO relied on and that the DPP reviewed in making the decision not to prosecute.

The court disagreed.  It found the terms of the limited waiver to be very clear.  Privilege is not waived generally because a privileged document has been disclosed for a limited purpose.  It is in the interests of justice for a party to be able to make such a limited waiver of privilege without contemplating privilege being lost entirely. 

There was no previous authority cited that addressed squarely the question of whether the process of decision-making and judicial review of that decision formed one single composite process “such that waiver for one meant waiver for all”.  The court found no “inevitable or necessary nexus” between the advice provided to the DPP together with the decision on prosecution on the one hand, and the judicial review of that decision on the other.  Rather, between the process of decision-making and the challenge of that decision there is in fact “a fundamental separation of function and responsibility. The latter is not a “composite part of the former”. The court felt it would “strongly against the public interest” if whenever one government department waives privilege to assist another, that waiver might be extended to cover subsequent judicial reviews.


These decisions are helpful reminders of the risks inherent in deliberate or inadvertent partial waiver of privilege, and the opportunities available to the party receiving such documents to challenge the extent of the waiver.

The clear decision on the scope of the Government’s express limited waiver provides useful guidance about the high threshold that needs to be met for a limited waiver of privilege in respect of one set of proceedings, or one aspect of a judicial process, to be extended by the court to cover related proceedings or processes.

With respect to inadvertent disclosure of privileged material, while many practitioners are familiar with the concept of “obvious mistake” on inadvertent disclosure, the judgment is a helpful reminder that (despite CPR 31.20) this is not a straightforward test and only if the mistake would be obvious both subjectively to the solicitor receiving the disclosure, and objectively to any reasonable solicitor, will the disclosing party be likely to succeed in persuading the court to prevent this material being used. 

The firm dismissal of the cherry-picking argument raised in the same hearing, however, provides comfort that inadvertent waiver is unlikely to have wider ramifications in terms of unpicking privilege over related documents. It is clear that cherry-picking arguments will only succeed in circumstances where the selective deployment of privileged material is intentional, not inadvertent.


1 Mohammed Al Fayed et ors v The Commissioner of Police for the Metropolis et ors [2002] EWCA Civ 780).

Further information

This case summary is part of the Allen & Overy Litigation and Dispute Resolution Review, a monthly publication.  If you wish to receive this publication, please contact Amy Edwards, ​