What you need to know about privilege waivers in legal cases

With thanks to David Mulholland, Quality Assurance Team Leader at Fieldfisher Condor, for authoring this article.

Under disclosure rules law firms, as legal representatives of a party to a dispute, must ensure that any claim to withhold a document on the grounds of privilege is properly justified and supported by clear reasoning.

There are four main types of privilege that may apply:

1. Legal advice privilege - Legal advice privilege applies to communications between a client and their legal representatives (including solicitors and in-house legal counsel) regardless of whether court proceedings have started. Legal advice privilege gives clients full confidence in their communication with their lawyer. It ensures that clients can communicate freely with their lawyers without fear of that communication being disclosed.

To attract legal privilege, a document must:

Be a confidential communication;
Exist between a client and their lawyer; and
Have the dominant purpose of seeking or providing legal advice. If a document is not confidential, for example, if it has been shared with third parties, then legal advice privilege does not apply. This type of privilege remains until and unless a client chooses to waive it.

2. Litigation privilege - Litigation privilege only applies when litigation has begun or is reasonably contemplated. A helpful rule of thumb is to assess documents that have been sent to/from legal advisers. Where a document has been created with litigation in mind, the dominant purpose of the document must concern that litigation.

To qualify for litigation privilege, the document must:

Be a communication between the lawyer and the client, or between either of them and a third party; OR
Be a document created by or on behalf of the client or the client’s lawyer; AND
Created for the dominant purpose of litigation; AND
Relate to adversarial (not investigative) litigation, which is pending, reasonably contemplated or existing.

The litigation must be a real likelihood rather than a mere possibility, but does not need to have a greater change than 50% of occurring.

3. Common interest/Joint interest privilege - This type of privilege occurs when two or more parties jointly seek legal advice and share the same interest in the matter, allowing them to maintain confidentiality of their communications. Examples include:

joint retainers, where multiple clients instruct the same solicitor
Corporate structures, such as a parent company and subsidiary sharing legal advice.
Insurer-issued relationships, where legal advice is given in the context of a claim.

4. Without prejudice privilege ("WPP") - WPP is distinct from legal professional privilege as it is a rule of evidence. It protects settlement discussions by ensuring that confidential communications made in a genuine attempt to resolve a dispute cannot be used in court.

The following elements need to be satisfied for WPP to apply:

There MUST be communication between the parties to the dispute.
The content of the communication must be confidential.
A real dispute must exist – business negotiations do not qualify
A clear intention to invoke WPP (although labels like "without prejudice" are not determinative).

WPP

Joint or Common Interest Privilege

NOTE

Shared Privilege – Cannot be waived unilaterally—all parties must agree.
Confidentiality – Applies to both written and oral communications.
Existing Dispute – WPP only applies if a dispute exists at the time of the communication.
Clear Intention – The presence or absence of a label is not determinative (Meaker v Cyxtera Technology UK Ltd [2023]).

Joint and common interest privilege allow multiple parties to retain privilege over a document without waiving it, provided they share a legal interest.

Distinctions:

Joint Interest Privilege – Arises when parties share the same lawyer under a joint retainer (e.g. co-defendants).
Common Interest Privilege – Applies when parties have separate lawyers but share a legal interest in the privileged material (e.g. insurer and insured).

Exceptions – When WPP Material Can Be Used in Court:

NOTE:

Privilege remains intact when shared among those with a common legal interest.
Cannot be unilaterally waived—all parties must consent.
Best practice: Formal agreements should document shared privilege arrangements.

Although WPP communications are ordinarily protected, they may be disclosed in exceptional circumstances, such as:

Allegations of fraud, misrepresentation, or undue influence.
When justice requires disclosure of WPP material.

Examples of Privileged vs Non-Privileged Documents

Likely to be Privileged	Likely not to be privileged
Notes/opinions from counsel/solicitors	Public communications i.e. letters to MPs / communication with media
Emails from lawyers containing advice	Documents produced for mainly non legal purposes
Emails from employees to lawyers asking for legal advice on topics	Filed pleadings
Drafts of pleadings/letters	Letters between parties (unless Without Prejudice Privilege applies - see below)
Committee papers drafted by lawyers	Communications between non lawyers (unless repeating legal advice)
Extracts of minutes containing legal advice	Legal advice given from a non-lawyer i.e. an accountant
Repetition or extracts of the above within for example work email correspondence	Evidence created before legal advice was given e.g. Audit reports

Loss of Privilege via Waiver

Unintentional waiver of privilege

Privilege may be inadvertently waived when:

A party references legal advice in witness statements or submissions.
A party asserts that their actions were based on legal advice.

Privileged material is included in a compilation document.

Privileged material is shared too widely, losing confidentiality.

Once privileged is lost, it cannot be reinstated. Courts have discretion to limit the use of inadvertently disclosed privileged material. For example, in PCP Capital Partners LLP v Barclays Bank Plc [2020] EWHC 1393 (Comm), the court determined that PCP was entitled to further disclosure on the basis that Barclays had waived privilege by referencing legal advice in witness evidence and opening submissions. Conversely, in Pickett v Balkind [2022] EWHC 2226 (TCC), the High Court declined to grant an injunction to prevent the use of privileged material mistakenly included in a witness statement exhibit.

It is critical that documents are thoroughly reviewed before disclosure to prevent inadvertent waiver.

Intentional Waiver of Privilege

Privilege may be deliberately waived in specific legal or commercial circumstances.

Common Reasons for Intentional Waiver:

Supporting a Legal Argument – e.g., disclosing legal advice to demonstrate compliance with the law.
Responding to an Opponent’s Disclosure – e.g., countering an opponent's reliance on privileged material.

Public Policy Considerations – e.g., The Post Office Horizon IT Inquiry, where privilege was waived for transparency.

Intentional waivers of privilege are rare and should only occur with explicit client instructions.

Conclusion

Privilege waivers most often occurs due to inadvertent disclosure, thereby highlighting the need for meticulous document review during disclosure exercises. Whilst privilege may be intentionally waived for strategic or public interest reasons, without prejudice and joint interest privilege can only be waived with the consent of all relevant parties.

By carefully managing privilege claims, lawyers can ensure confidentiality is maintained, mitigate litigation risks, and protect their clients’ legal position.