Legal professional privilege

What is protected by legal professional privilege?

Litigation privilege

Litigation privilege affords a wider protection than legal advice privilege since, where it applies, it can protect communications with third parties as well as those between a lawyer and their client. Litigation" in this context extends to the vast majority of civil and criminal proceedings, arbitration and employment proceedings. It applies where adversarial proceedings are existing or are reasonably in prospect (for instance, where one party sends or receives a formal letter before action). " The test is whether proceedings are adversarial in nature. It will often be obvious when matters are merely inquisitorial or litigious, but difficulties can arise in the context of investigations and inquiries. Each case will depend on the facts. While there is no single test for what constitutes adversarial proceedings, the following are indicators: The circumstances go beyond a simple factual inquiry and there is some indication of confrontation and conflict (as suggested by "adversarial").

If adversarial proceedings are existing or reasonably in prospect, the 'dominant purpose' test will apply to protect as privileged confidential  communications prepared for the dominant purpose of giving or obtaining legal advice with regard to that litigation or aiding the conduct of that litigation such as collecting evidence or information. Determining the dominant purpose of a document can be difficult where there are competing purposes. The preparation of the communication for litigation has to be the prevailing or most influential purpose; where there are two purposes to a document of equal importance, litigation privilege will not apply (although the court may sometimes treat two related purposes as part of a single overarching purpose).

Litigation privilege has no retrospective effect.

Documents created before adversarial proceedings are reasonably in prospect will not attract litigation privilege (although they may attract legal advice privilege).

Legal advice privilege

If no adversarial proceedings are in contemplation, legal professional privilege will only attach to documents which constitute confidential communications between a lawyer and their client made for the dominant purpose of giving or obtaining legal advice and documents which evidence such communications, including material forming part of the continuum of those communications. Each part of this test requires further explanation.

Communications

To attract legal advice privilege, a document must actually transfer information between a lawyer and their client or be intended to transfer information (even if it is not in fact transferred or sent), or constitute part of a lawyer's drafts, attendance notes and memoranda that ultimately inform the lawyer's legal advice. A document which is not prepared for the dominant purpose of being placed before a lawyer for the purpose of seeking legal advice or is not addressed and delivered to a lawyer specifically for advice may not constitute a communication; however, it may be capable of protection as an "inchoate" communication (a document intended to be a communication between a lawyer and a client for the dominant purpose of seeking or receiving legal advice that was never communicated) or as part of a lawyer's working papers, where such a document remains in the hands of a lawyer.

Lawyer

Includes all members of the legal profession: solicitors, in-house lawyers, barristers within the UK and duly accredited foreign lawyers (whether foreign in-house counsel who are not required to be a member of their local Bar would still qualify is currently untested). Where appropriate provisions for supervision are in operation, it can also include legal executives, paralegals and trainee solicitors. Difficulties arise with respect to communications with in-house lawyers where the context of the communication relates to commercial rather than legal matters and any other context in which lawyers are not acting in a professional capacity. Where that is the case, privilege will not apply.

Client

Not every employee in a company will be the client for the purpose of legal advice privilege. In the context of a corporate client, the 'client' will only comprise those individuals who are authorised to seek or receive legal advice from a lawyer, , whether external or in-house. This might be an ad hoc committee or group formed to respond to a specific issue or incident, or it might be members of senior management.

Documents created for the purpose of giving or obtaining legal advice

Legal professional privilege only attaches to communication that’s created for the dominant purpose of giving or seeking legal advice as to what should prudently and sensibly be done in a relevant legal context. This includes advice on how best to present facts in light of legal advice given. In determining whether there is a relevant legal context, consideration should be given to whether the advice relates to 'the rights, liabilities, obligations or remedies of the client either under private law or under public law'. Privilege will not attach to advice which is purely commercial or strategic. Where a document contains both a privileged and a non-privileged communication (such as purely strategic advice), such documents may be withheld from disclosure in part rather than as a whole.

Note that documents which constitute secondary evidence of a privileged communication can be protected by legal advice privilege.

Further difficulties can arise if privilege has been impliedly or expressly waived. These issues are beyond the scope of this brief summary.

Legal professional privilege in the context of criminal investigations

Regulatory investigations in the UK are not automatically considered to be adversarial from the outset and litigation privilege may not always apply, depending on the circumstances. The result is that legal advice given in the context of such an investigation will attract legal advice privilege, but documents including notes, interview transcripts and / or expert reports for the purpose of giving advice or evidence may not always attract litigation privilege and could therefore be disclosable to a regulator or in subsequent litigation.

Litigation privilege will apply in any case once it is clear the investigation is sufficiently adversarial. Whether prosecution will be in reasonable contemplation for example, is a question of fact in each case and does not require a formal criminal investigation to have commenced or a decision to prosecute to have been made. Nor does it require the defendant to have full details of what might emerge in the investigation or complete certainty that proceedings will be initiated. Litigation privilege may also apply at an earlier stage, if the investigation process itself has become sufficiently adversarial so that the company under investigation effectively stands accused of wrongdoing and should, therefore, be able to claim litigation privilege over witness evidence gathered for the purpose of obtaining advice to defend itself.

Are communications with in-house counsel protected by legal professional privilege?

Yes.

An in-house lawyer must, however, take particular care to ensure that they distinguish clearly between advice which is legal and that which is commercial in nature, since the latter will not be protected by legal advice privilege. The in-house lawyer must also take care when instructing external lawyers to clearly identify and effectively manage the relevant lawyer / client relationships.

Does legal professional privilege apply to the correspondence of non-national qualified lawyers?

Yes, where the question of disclosure is governed by the law of England and Wales. Legal professional privilege applies to advice given by all duly accredited members of the legal profession. It is not necessary for the lawyer to be qualified in England and Wales. The question of whether this extends to in-house counsel in European jurisdictions where those counsel are not required to be members of their local Bar and whose advice in their own jurisdictions would not be protected by local professional secrecy laws remains to be determined by the UK courts.

Where the question of disclosure is governed by European law (such as in the context of an antitrust and competition investigation within the UK by the European Commission), only the advice of an independent lawyer qualified within the EEA is protected by legal professional privilege.

How is legal professional privilege waived?

Legal professional privilege can be waived in the following ways:

• Express or limited waiver: A litigant is entitled to deliberately waive privilege. It is possible to waive legal professional privilege on a selective basis so that disclosure to a third party of a privileged document will not mean that it ceases to be privileged for any other purpose. However, for a waiver to be selective, the terms of the disclosure must be clearly established in advance. This is a complex area. Always seek legal advice.
• Collateral waiver: This encompasses scenarios where a party has waived privilege over a document and "cherry-picked" that material. Further disclosure might be ordered by the court in the interest of fairness.
• Inadvertently: For example, by error in a disclosure exercise. Where privilege has been inadvertently raised, it can be clawed back where there has been an obvious mistake.

Note the general rule is that if a privileged document is relied on (no matter how it is used or referred to), that will generally constitute a waiver.  

Communications/documents which were brought into existence as part of or in furtherance of an iniquity (such as fraud) cannot be protected by legal professional privilege. A document which is shared with the world – for example, via a press release or publication, will no longer be confidential and cannot be protected by privilege.

Legal professional privilege in the context of merger control

It is usual for merging parties to engage in pre-notification discussions with the CMA during which it is the CMA's practice to send the parties detailed questions concerning the transaction. Further questions from the CMA are likely after the formal Merger Notice has been submitted, for example, to respond to information concerning the transaction that the CMA has received from third parties such as customers of the merging parties. Such requests for information supplement the information that the parties are required to submit under the terms of the Merger Notice.  Once the filing is made, the CMA has wide statutory powers to require the parties to produce information and documents for the purpose of the investigation (section 109 of the Enterprise Act 2002). However, the parties are not required to disclose legally privileged documents. In the area of merger control (as in other areas of English law), privilege refers to legal advice privilege and litigation privilege discussed above.

As a starting point, legal advice privilege attaches to communications between a client and their lawyers and, once established, remains in force unless and until it is waived (Addlesee and ors v Dentons Europe LLP [2020] EWHC 238 (Ch)). However, in University of Dundee v Chakraborty [2022] EAT 150 it was held that where a document was not privileged at the time of its creation, it cannot in any case become retrospectively protected by legal advice privilege at a later date. What matters is the privilege status of a document when it is created.

In Al Sadeq v Dechert & Ors [2024] EWCA Civ 28, the Court of Appeal considered whether litigation privilege can be claimed by non‑parties, and clarified the scope of the iniquity exception to privilege. The Court held that privilege may be lost where there is a prima facie case of iniquity, as long as there was abuse of the lawyer-client relationship. Importantly, the applicable threshold for the iniquity exception to legal privilege is now on "the balance of probabilities": the alleged iniquity (most commonly fraud) must be more likely than not on the material available to the decision‑maker at the time the disclosure decision is taken. Where the iniquity exception is engaged, privilege does not apply to documents and communications created as part of, or in furtherance of, the iniquity. This includes documents that report on or reveal the iniquitous conduct. The Court also confirmed that documents created in preparation for the iniquity, as well as those generated afterwards, may still fall within the exception. Turning to litigation privilege, it was confirmed that, provided the dominant purpose test is satisfied, litigation privilege can extend to non‑parties. This includes circumstances where, as in this case, the party asserting privilege was not a party to the underlying proceedings but was a victim of the alleged wrongdoing.

In WH Holding v E20 Stadium LLP [2018] EWCA Civ 2652 the Court of Appeal confirmed that "conducting litigation" includes taking steps to avoid or settle litigation. However, to be covered by litigation privilege, the communications must have been made for the dominant purpose of obtaining advice or evidence in relation to the conduct of that litigation, rather than "conducting litigation" in a broad sense. This also extends to making decisions about whether to settle a dispute, but the Court of Appeal rejected the attempt to extend the scope of litigation privilege to cover purely commercial discussions, maintaining that the disputed documents (being emails between board members discussing a commercial proposal for the settlement of a dispute), were not covered by litigation privilege.

Further to commercial decision making, in Jardine Strategic Limited v Oasis Investments II Master Fund Ltd [2025] UKPC 34, the Privy Council held that the long‑standing Shareholder Rule, which prevented a company from asserting legal professional privilege against its shareholders, had been abolished. As a result, companies involved in disputes with shareholders are now able to assert privilege against both current and former shareholders, provided that the usual requirements for legal professional privilege are otherwise satisfied. This decision represents a significant development for companies, strengthening their ability to protect privileged communications in the context of shareholder disputes.

Case law has also clarified how legal professional privilege operates within corporate structures, particularly in relation to internal communications. In Aabar Holdings S.A.R.L. & Others v Glencore Plc & Others [2026] EWHC 877 (Comm), the High Court confirmed that privilege applies only to communications between a company’s lawyers and a defined “client group”. The concept of a "client group" extends only to those employees authorised to seek and receive legal advice on behalf of the organisation, therefore communication between lawyers and those who do not fall into that category of a "client group" does not attract privilege. This decision highlights the importance of identifying who is authorised to engage with lawyers early on.

In relation to investigations, the Court of Appeal in Sports Direct International plc v The FRC [2020] EWCA Civ 177 held that, save for investigations by The Law Society and the SRA, regulators cannot compel the production of privileged documents belonging to a third party when investigating a regulated person (such as an auditor). Any ability to override legal professional privilege would require clear and express statutory powers by the courts.

Interestingly, the High Court in Suppipat v Siam Commercial Bank Public Company Ltd [2022] EWHC 381 (Comm) confirmed that legal professional privilege may be maintained even where an opposing party has lawfully obtained privileged documents in a foreign jurisdiction. In that case, the claimant companies had accessed the documents through subpoenas issued in Thailand. The Court held that this did not, of itself, result in a loss of privilege. It confirmed that the inadvertent disclosure of privileged material, or disclosure by a third party, does not without more amount to a waiver of privilege.

Content to follow shortly.