National Crime Agency v DP: how the Employment Appeal Tribunal reinterpreted Section 56 of the Investigatory Powers Act 2016

The Employment Appeal Tribunal has issued a significant judgement clarifying the reach of Section 56 of the Investigatory Powers Act 2016 ("IPA") in the employment law context. The decision in National Crime Agency v DP and others [2026] EAT 52, handed down by His Honour Judge James Tayler on 15 April 2026, resolves a question that had not previously been considered at appellate level: whether an employee who has worked in a role involving intercepted communications can attend an open Employment Tribunal hearing of their own claim.

Section 56 IPA prohibits, in sweeping terms, any evidence, question, assertion, disclosure or "other thing" done in connection with legal proceedings that tends to suggest interception-related conduct has, or may have, occurred. The National Crime Agency argued that this provision applied to any mention of an employee's role dealing with intercepted material — with the consequence that the entire proceedings would have to be conducted in closed, excluding the claimant entirely and preventing disclosure of any evidence to them even through a Special Advocate.

HHJ Tayler rejected that construction. Applying the interpretative obligation under Section 3 of the Human Rights Act 1998, and drawing on the Supreme Court's analysis in Mercer v Alternative Future Group Ltd [2024] UKSC 12, the judgement held that such a literal reading was incompatible with Article 6 fair trial rights and would produce manifestly disproportionate results. By way of illustration, the judgement noted that, on the NCA's interpretation, an employee who had unlawfully intercepted communications could attend their own tribunal hearing by virtue of a specific Schedule 3 exception — yet a blameless employee whose role involved lawful interception could not.

The resolution adopted by the EAT was to read Section 56(1)(b) IPA as applying only to particular interception-related conduct — a term chosen deliberately over "specific" to afford a sufficiently flexible but meaningfully bounded protection. Whether conduct is "particular" will fall to be determined by Employment Tribunals on the facts, having regard to the seriousness of any national security prejudice, the risk of disclosure, and the extent to which an employee's fair trial rights would be infringed by exclusion.

This approach preserves the discretionary character of the closed procedure that the Supreme Court in Tariq v Home Office [2011] UKSC 35 held to be compatible with Convention rights — precisely because it requires a judicial balancing exercise rather than automatic exclusion. As the judgement observed, the lawfulness of the closed procedure has always rested on the Employment Judge's ability to weigh competing interests and keep any restrictive orders under review. The NCA's construction would have made closed proceedings mandatory, eliminating that judicial oversight entirely.

The EAT also relied on the well-established principle from R (Unison) v Lord Chancellor [2017] UKSC 51 that even where Parliament authorises an intrusion on access to justice, the degree of intrusion must not exceed what the measure's objectives require. Section 56 IPA exists to prevent sensitive information entering the public domain — not to exclude employees from hearings that will, in many cases, involve no sensitive information at all.

The judgement does not dispose of the individual appeals, which will proceed to further submissions. Parties have 14 days from hand-down to provide written submissions on the next stages, including whether closed material should be made available to the claimants and what protective orders may be required.