In a recent decision, the High Court has refused an injunction to prevent the claimants' use of privileged material which the defendants claimed to have disclosed in error: Flowcrete UK Ltd v Vebro Polymers UK Ltd [2023] EWHC 22 (Comm).

While the court can intervene to prevent use of privileged documents where they have been provided to the opponent in error in the course of a disclosure exercise, it will not generally do so unless disclosure was procured by fraud or was an obvious mistake. The present decision highlights that the burden is on the disclosing party to establish both that the documents were provided by mistake and that the mistake was obvious, and the court may take a strict approach in deciding whether that burden has been met.

The decision also acts as a reminder that, even where an obvious mistake has been made, the court may refuse injunctive relief where the documents disclose wrongdoing or inappropriate conduct (as the court did in Pickett v Balkind [2022] EWHC 2226 (TCC), considered here). The threshold appears to be lower than for a finding that the material was not privileged in the first place under the "iniquity principle" (ie that there is no privilege for communications made in furtherance of a crime, fraud or equivalent conduct). In the present case, had the court considered an injunction otherwise justified, it would have refused relief in respect of one category of documents which he said raised questions as to whether a witness statement of one of the defendants contained his own independent evidence.

Finally, the decision is of interest in confirming that litigation privilege is not restricted to communications between a party or its lawyers and third parties - a point that is sometimes questioned. While the point was conceded, it is clear that the court agreed with the concession.


The claimants brought proceedings against various former employees who had set up a competing business, alleging that in doing so they had misappropriated and misused the claimants' confidential information.

On 14 June 2022, the defendants disclosed some 3,788 documents by way of extended disclosure. This included two pdf documents (the "PDFs"), which totalled 800 pages and were compilations of other documents, including some documents which were not disclosed elsewhere in the defendants' disclosure.

The claimants wrote to the defendants in mid-July and the beginning of August setting out their concerns about various aspects of the defendants' disclosure, including the PDFs. The defendants responded on 17 August, asserting that the PDFs were subject to legal advice privilege and litigation privilege and had been inadvertently disclosed, but (as the court later found) without providing a proper explanation as to the bases for these assertions.

On 26 September, for the first time, the defendants identified which individual documents in the PDFs they alleged were privileged. On 4 October, they applied for an injunction preventing the claimants using the documents within the PDF that they said were privileged and were inadvertently disclosed. By the time the application was heard, the scope of the defendants' application had narrowed so that only litigation privilege was asserted and only in respect of the following categories of individual documents within the PDFs (referred to as "the Disputed Documents"):

  1. Emails addressing projects lost as a consequence of an injunction obtained by the claimants earlier in the proceedings.
  2. Emails relating to the identification of projects to be carved out of the undertaking put in place in relation to the injunction.
  3. Emails relating to the drafting and execution of the fourth defendant's witness evidence for the purpose of the claimants' injunction application.


The High Court (Mr Nigel Cooper KC sitting as a High Court Judge) dismissed the defendants' application for an injunction to prevent use of the Disputed Documents.

Litigation privilege

The judge noted that the question was whether the individual Disputed Documents were privileged. There was no wider privilege in the PDFs (as a selection of a party's own unprivileged documents, as opposed to a selection of third party documents, cannot be privileged even if it betrays the trend of legal advice: Sumito Corp v Credit Lyonnaise Rouse Ltd [2001] 1 WLR 479).

There had been some debate between the parties as to whether the Disputed Documents could be covered by litigation privilege, as they were not documents passing between the defendants or their solicitors and third parties. However, by the time of the hearing the claimants were prepared to proceed on the basis that litigation privilege was available in principle. The judge said he considered that to be a sensible position, including because preparatory materials may fall within the scope of litigation privilege even if they do not involve communication with a third party. The modern test, as set out in Waugh v British Railways Board [1980] AC 521, is whether a document "was produced or brought into existence. with the dominant purpose of. using it or its contents in order to obtain legal advice or to conduct or aid in the conduct of litigation. in reasonable prospect".

Inadvertent disclosure

Under para.19.1 of CPR PD 57AD (which replaced the disclosure pilot rules at PD 51U), where a party inadvertently produces a privileged document on disclosure, the recipient may use it or its contents only with the court's permission. This provision is not materially different to CPR 31.20, which was considered in Al Fayed v Commissioner of the Police of the Metropolis [2002] EWCA Civ 780. That decision established, in summary, that where a party has given inspection of privileged documents by mistake, it will generally be too late to correct the mistake by obtaining injunctive relief. The court can however intervene to prevent use of the documents where justice requires, such as where inspection has been procured by fraud or is the result of an "obvious mistake".

The judge stated that the burden of establishing inadvertent disclosure was on the defendant in this case, and the evidence produced was "limited and unsatisfactory". Accordingly, the defendant had not discharged that burden.

As for obvious mistake, the judge noted that the relevant question was not whether it was obvious that the documents were privileged, but whether a reasonable solicitor would have realised that a mistake had been made. In the present case, if the judge had been satisfied as to inadvertent disclosure, he would still have refused injunctive relief on the basis that there was no obvious mistake. He rejected the argument that simply looking at the PDFs should have raised a red flag. While one might expect to receive native e-mails and associated attachments in a disclosure exercise, provision of a PDF compilation would not be sufficient to put the claimants on notice that the PDFs might contain privileged material which had been disclosed by mistake. Nor did the fact that each document within the PDFs was headed "" indicate that the documents were potentially privileged and were not intended to be provided for inspection. That reference was equally consistent with an intention that the documents should be disclosed.

The judge said there was more force to the defendants' submission that the nature of the Disputed Documents would have suggested that the documents were disclosed by mistake, as they related to preparation of the defendants' response to matters relating to the injunction and to preparation of a witness statement. However, the judge did not consider that this factor alone was sufficient to put the claimants or their solicitors on notice of an obvious mistake. The documents were included within a compilation of obviously non-privileged documents. And, as the judge accepted, a party may have reasons for disclosing privileged documents and "it is not for a recipient to second guess why disclosure has been made unless an obvious mistake has been made". None of the documents were marked privileged or of a type that was obviously privileged, and no lawyers were copied in on the correspondence. It was also relevant that the defendants did not immediately raise the question of privilege and inadvertent disclosure when the issue arose.

Just and equitable

The judge noted that, even where there is an obvious mistake, the court still has to consider whether it is just and equitable to prevent the use of the privileged material. The claimants challenged the grant of the injunction on two grounds under this heading: (i) delay; and (ii) that some of Disputed Documents disclosed prima facie wrongdoing or inappropriate conduct.

In relation to delay, the judge stated that it was incumbent on a party in the defendants' situation to act without delay in asserting and identifying the privilege claimed, and the defendants in this case did delay in properly asserting privilege. However, if he had been satisfied that the Disputed Documents were inadvertently disclosed pursuant to an obvious mistake, he would not have refused an injunction solely on the basis of that delay.

As to wrongdoing or inappropriate conduct, the judge noted that this principle does not depend on dishonesty but is wider in scope, as established in Pickett (referred to above). In that case the judge identified the relevant question as whether it would be unconscionable for the recipient of the privilege document to seek to rely on it: if it would not be unconscionable then it would not be appropriate to grant an injunction. The judge in the present case rejected the defendants' submission that the test of unconscionability as laid down in Pickett set the bar too low. In his view, the decision was consistent with the authorities, including Al Fayed, and was correct as a matter of principle considering that the court is exercising an equitable jurisdiction.

In considering whether the Disputed Documents disclosed sufficient evidence of wrongdoing to justify refusing injunctive relief, the judge said, it was necessary to consider each of the three categories of Disputed Documents listed above individually. In relation to the first two categories, which the claimants submitted showed inconsistency between the defendants' counterclaim and they way they had collated the evidence in support of that counterclaim, and a breach or intended breach of a confidentiality agreement made for the purposes of the proceedings, the judge said he would not have held that the documents evidenced conduct that was sufficiently unconscionable to justify refusing the injunction.

In relation to the third category, however, the judge accepted that the documents raised questions as to the extent to which the fourth defendant's witness statements had been influenced by the first defendant's marketing director and the other defendants. As such, he would have held that there was sufficient evidence of unconscionable conduct to justify refusing injunctive relief.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.