The Appellant in his capacity as representative of an unrecognised union lodged a collective grievance on behalf of the employees who were at risk of redundancy, taking various points about the conduct of the assessment centre at which employees were selected for redundancy. He was later forwarded a photograph copy of a manager's notes (the manager had not been part of the assessment panel), which contained adverse comments about the selected individuals. The manager who had made the notes had not given consent to them being copied or distributed.

The appellant union representative showed the copied notes to the HR manager and said he would use them as evidence. He was later dismissed for storing and sharing private and 'confidential information that is the property of a manager.'

Under S.152 of the Trade Union and Labour Relations (Consolidation) Act 1992 the dismissal of an employee shall be regarded as unfair if the reason for it (or, if more than one, the principal reason) was that the employee had taken part, or proposed to take part, in the activities of an independent trade union at an appropriate time. The equivalent right in NI is contained in Article 136 of the Employment Rights (NI) Order 1996.

The question was whether receipt, storage and use of this confidential information fell within the definition of trade union activities. The original tribunal thought it did. The EAT thought it did not - retention of unlawfully obtained information should not be covered by the protection in legislation - and referred the matter back to tribunal to determine the reason for dismissal. Mr Morris appealed and the Court of Appeal has found in his favour, taking a more nuanced view of the work of a trade union representative:

"It cannot be uncommon for a union representative to be given, without soliciting it, information which he realises has been obtained without the owner's consent, whether orally or in the form of a copy document – to be, in other words, the recipient of a leak; and of course that can occur in other contexts too. Such a situation can be invidious for the recipient because it involves competing interests, and how to behave is not always straightforward. A strict moralist might say that the only correct course is to decline to receive the information in the first place or, if it is too late for that, to make no use of it whatever and destroy any record. Slade J [the EAT judge, who sat alone] seems to have thought that that was what the Appellant should have done here. There may be circumstances where that is indeed the only right course (as it generally is, for example, when a lawyer is offered, or given, confidential information that he or she knows has been obtained without the owner's consent); and perhaps that would, by the highest standards, have been the correct way for the Appellant to respond in this case. But we are not here concerned with an ethics seminar. Regrettably (in hindsight), neither the ET nor the EAT sat with lay members, and I am reluctant to give any general guidance about what good industrial relations practice would require in such a case. But the question here is more specific, namely whether the very limited way in which the Appellant made use of the leaked information, which directly concerned his members as individuals and which it was in their interest for him to follow up, was a sufficient departure from good industrial relations practice to take his conduct outside the scope of "trade union activities" for the purpose of section 152... As to that, I cannot believe that it was."
http://www.bailii.org/ew/cases/EWCA/Civ/2018/1358.html