UK EAT warns over unchecked 300-page ChatGPT skeleton argument

The UK’s Employment Appeal Tribunal criticised an unchecked, 300-page ChatGPT skeleton argument in a judgment dated 17 September 2026, reported by the Law Society Gazette on 18 September.

In an appeal from England and Wales, the EAT found that an appellant had submitted an unchecked ChatGPT argument and tried to make opponents identify its errors. No reliance was placed on the document at the preliminary hearing. The tribunal warned of future rejection of such filings; one appeal ground proceeded.

What did the tribunal find?

In Hancox v Sutherland and others [2026] EAT 139, the appellant filed the document on 27 July 2026, before a preliminary hearing on 29 July. The judgment records almost 132,000 words across 300 pages (paragraph 82). His covering email asked opponents to identify inaccuracies by 4pm the following day (paragraph 83).

At the hearing, the appellant acknowledged that much of the document lacked credibility. Paragraph 85 records that he had used ChatGPT because preparation time was short, without checking accuracy or procedural compliance. The filing went unused.

At paragraph 86, the tribunal said: “It was for the Appellant to take responsibility for the contents of his own written argument.” Paragraph 87 warned that a similar document would likely be rejected in future, with other enforcement powers considered. It imposed no monetary sanction for this filing.

How does the page-length rule compare?

The EAT Practice Direction 2024, paragraph 11.6.6(a), says skeleton arguments in England and Wales should generally run to 5–15 pages. Above 20 pages, the judge may require a shorter version or reduce oral-submission time. Those are discretionary responses. Paragraph 6.1.10 applies the skeleton requirements to preliminary hearings too.

SafeLegalAI’s comparison of the two documents puts the July filing at 15 times the 20-page threshold: 300 divided by 20. That arithmetic describes its scale; the direction does not make crossing the threshold an automatic dismissal of the appeal. The judiciary’s publication page confirms that the direction applies to procedural steps from 1 February 2025, including in older appeals.

What follows from this decision?

The appeal continues on one ground. The judgment separates the filing criticism from whether an arguable error of law exists: the surviving ground concerns adequate notice of a strike-out application and a fair opportunity to oppose it (paragraph 142). The warning does not establish that particular authorities in the ChatGPT document were invented.

• Verification remains the submitting party’s responsibility, not the opponent’s (paragraph 86).
• Excessive length can attract procedural consequences without a finding of fabricated citations (paragraphs 84–87).
• The warning about future rejection is distinct from a sanction imposed in this case (paragraph 87).

Record: Hancox v Sutherland.

Sources

• Hancox v Sutherland and others [2026] EAT 139, judgment dated 17 September 2026, paragraphs 18–21, 82–87 and 142.
• Employment Appeal Tribunal Practice Direction 2024, paragraphs 1.2.1, 6.1.10 and 11.6.6(a).
• Judiciary publication and applicability notice, 18 October 2024.
• Law Society Gazette, report published 18 September 2026. Reporting date only; the judgment supplies the findings.