HSBC Asia Holdings BV v Gillespie

An employment tribunal has power to exclude evidence which is theoretically relevant but insufficiently relevant to justify its admission. Relevance is a matter of degree and must be weighed against inconvenience, expense, delay and oppression. Preliminary rulings require caution, but may be appropriate where the evidence would generate substantial cost or materially affect the hearing.

In discrimination claims, evidence of a wider discriminatory culture may be relevant to whether particular acts occurred, their motivation, or the existence of a hostile environment. However, alleged incidents involving different people, in different departments and many years earlier may be too marginal to admit. A tribunal cannot compel a claimant to proceed only on sample claims without agreement, although it may split large numbers of claims into successive tranches as a carefully considered case-management measure.

The claimant brought discrimination, harassment, victimisation, whistleblowing and unfair-dismissal claims against companies in the HSBC group. She relied on alleged sexual-harassment incidents in earlier postings in the Far East and at Chiswick as background to complaints arising from her employment in the Group Risk Department in London.

At a pre-hearing review, the Employment Judge held the background allegations admissible and declined to require the claimant to proceed by sample claims. HSBC appealed. The appeal principally concerned whether the tribunal had power to exclude the alleged background evidence for insufficient relevance, and whether it could restrict the prosecution of properly arguable pleaded claims.

1. Appeal allowed on admissibility. The Employment Judge had misdirected himself by treating the authorities as preventing any restriction on background evidence and by applying a test of intrinsic or patent irrelevance. The tribunal had power to decide whether the evidence was sufficiently relevant to be admissible.
2. The basic rule is that relevant evidence is admissible and irrelevant evidence is inadmissible. Relevance is not absolute. Evidence may be theoretically relevant yet too marginal to justify admission when its probative value is weighed against inconvenience, expense, delay or oppression. The same principle applies in employment tribunals, which may have particular reason to exclude marginal evidence because proceedings are intended to be informal and inexpensive.
3. Although preliminary exclusion should be approached cautiously, it is justified where the evidence is self-contained, its relevance can reliably be assessed, and retaining it would impose substantial investigative, disclosure and hearing burdens. Discrimination claims may warrant advance case management because extensive historical allegations can obscure the essential issues.
4. Evidence of a discriminatory culture may assist in deciding whether particular acts occurred, whether they were discriminatory, or whether the statutory hostile, degrading, humiliating or offensive environment existed. Its relevance depends on the relationship between the alleged culture and the acts in issue. The earlier incidents here involved different individuals, departments and countries, and had only minor overlap with the pleaded Group Risk allegations. Their theoretical relevance was outweighed by the substantial cost and inconvenience of investigating them.
5. The evidence pleaded in paragraph 24 was therefore inadmissible at the hearing.
6. The challenge concerning sample claims was not pursued. In general, a tribunal cannot prevent a claimant from prosecuting a properly arguable pleaded claim merely because many similar claims exist. With agreement, parties may proceed on samples. Without agreement, the tribunal may, under rule 10(2)(i) of the Employment Tribunal Rules, hive off secondary or repetitive claims into a later tranche, but only after careful consideration and where the advantages are clear.

• Employment Appeal Tribunal: Allowed HSBC’s appeal on admissibility and directed that evidence of the paragraph 24 allegations was inadmissible. The challenge to sample claims was withdrawn.
• Employment Tribunal: Held the paragraph 24 allegations admissible, deferred time-limit issues to the full hearing, and declined to direct reliance on sample claims only.