An employer sent a letter marked "without prejudice" advising an employee that there was no prospect of his returning to work in any capacity where the employee was seeking to have the decision to dismiss overturned on appeal. The employee asserted that he was a whistleblower and the real reason for his dismissal was that he had made serious allegations against senior employees. The EAT held that the letter was not a genuine attempt by the employer to compromise a dispute such as to trigger the without prejudice rule. Further, the employer's reference to "unfounded allegations" in its letter amounted to unambiguous impropriety. Accordingly the letter was not privileged and was, therefore, admissible in evidence. (Hudson v University of Oxford).

In Mezzotero, Cox J arguably extended (in obiter comments) the application of the "unambiguous impropriety" exception to discrimination cases because of the fact-sensitive nature of such cases and the public interest in tackling discrimination. It is interesting to see Cox J at the EAT in Hudson taking the same approach to a whistleblowing case.