When Does Whistleblowing Become Harassment?

Key Lessons from Optosafe Ltd & Anor v Robertson [2026] EWHC 12 (KB)

The Law

To succeed with a civil harassment claim, a claimant must establish the following as set out within the Protection from Harassment Act 1997 (PFHA):

Whilst there is no definition of harassment within the PFHA, in the case of Hayes v Willoughby it was described as “a persistent and deliberate course of unreasonable and oppressive conduct, targeted at another person, which is calculated to and does cause that person alarm, fear or distress”.

In addition to the above, in the case of Majrowski v Guy’s and St Thomas’s NHS Trust it was said that the conduct relied upon must cross “the boundary between conduct which is unattractive, even unreasonable, and conduct which is oppressive and unacceptable. To cross the boundary from the regrettable to the unacceptable the gravity of the misconduct must be of an which would sustain criminal liability under Section 2”.

Only if the claimant is able to establish the above does the court go on to consider any defences pleaded by the defendant. A course of conduct does not amount to harassment if a defendant is able to establish that:

Background

In this case, the Second Claimant pursued a harassment claim against the Defendant in relation to emails and LinkedIn posts published between 4 February 2023 and 10 January 2024. The Defendant relied upon the defences set out within Section 1(3)(a) and (c) of the PFHA in support of his position. He argued that his course of conduct was pursued for the purpose of preventing and detecting crime and/or was reasonable because he was whistleblowing.

Decision

Course of conduct – The Judge concluded that the Defendant’s activities in sending emails and publishing numerous posts on LinkedIn constituted a course of conduct for the purposes of the PFHA. Interestingly, the Judge considered whether the course of conduct began in February 2023 or August 2023 given the gap in time between the two. The Judge ultimately concluded that because the character of the messages was consistent, despite the gap in time, the February 2023 messages were part of the same course of conduct as the August 2023 messages.

Amounts to harassment – One of the arguments run in defence was that some of the content may have had a factual foundation. The Judge therefore took this into account when deciding whether the course of conduct amounted to harassment. Ultimately, the Judge concluded that the course of conduct did amount to harassment (regardless of any factual foundation). The Judge noted that the conduct had all the additional elements of oppression, persistence and unpleasantness. The Judge also referred to the volume of messages and noted that there had been approximately 80 messages in just over 5 months.

Knew or ought to have known – The Judge concluded that the Defendant did know that his conduct amounted to harassment and that he knew that he had deliberately engaged in a campaign which was persistent, oppressive and unreasonable. The Judge confirmed even if he had concluded that the Defendant did not know, he would have concluded that a reasonable person in possession of the same information would think that the conduct amounted to harassment.

Section 1(3)(a) defence – the Judge confirmed that the Defendant had failed to satisfy that his predominant motive was to prevent and/or detect crime. It was apparent to the Judge that the predominant motive was retaliation with the aim of punishing those he believed had done wrong.

Section 1(3)(c) defence – The Judge concluded that the Defendant’s reliance on this defence had no merit. The Judge concluded that, even if he had concluded that some of his posts were whistleblowing, the way in which he acted by relentlessly posting on a public forum as well as sending many emails was not reasonable.

The Second Claimant was ultimately successful and a final injunction was granted prohibiting any further harassment.