Discovery: Relevance and Necessity of Documents Immaterial Where No Ambiguity in Discovery Order

The High Court has held that where there is no ambiguity regarding the terms of a discovery order, the relevance and necessity of documents outside of that order to the dispute, is immaterial to the question of whether those documents should be discovered.

In the case of Irish Airline Pilots Pension DAC v Mercer [Ireland] LTD T/A Mercer,the plaintiff sought damages from the defendant arising from its alleged failure to promptly sell €40 million worth of shares held in the plaintiff’s pension scheme after the decision was taken to sell those shares in February 2020. This failure allegedly resulted in losses to the plaintiff, arising from the fall in stock market valuations around March 2020, as a result of the Covid-19 pandemic.

The parties had agreed a category of discovery. However, having received discovery from the plaintiff, the defendant argued that the plaintiff had failed to fully comply with that agreed discovery. It said that by reference to its defence and the reasons supplied when seeking the discovery, additional documents should have been discovered. On that basis, it sought an order of further and better discovery from the court.

Decision of the court

Twomey J agreed that the omitted documents were relevant to the defence. Nevertheless, he went on to say that there was a significant difference in the court’s approach to determining whether a category of discovery should be ordered on the one hand and, on the other hand, to interpreting whether a category of documents fell within a category previously ordered.

It was accepted that the terms of the pleadings were relevant to a decision as to whether to grant discovery and the extent of that discovery. However, the matter before the court was not an application for discovery in which it was claimed that discovery should be granted for a category of documents relating to an issue raised in the defence. That stage of the proceedings was over, once the terms of a category had been agreed/ordered by the court.

Rather this was an application where the discovery had already been agreed and thus the role of the court was to interpret the terms of that agreed discovery, according to the normal rules of interpretation, to see to what extent those terms included the documents in dispute. In doing so, the court was obliged to use the “rules generally applicable to interpreting written instruments”.This meant that the natural and ordinary meaning of the words applied.3

The corollary of this principle was that if there was no ambiguity then there was no need to resort to the pleadings or the letter seeking discovery. Applying this logic to the case before him, he said that there was no ambiguity in relation to what documents were covered by the discovery here and so he refused the application for further and better discovery.


This case emphasises the importance of giving careful consideration when framing requests for discovery. It makes clear that even if the documents concerned are relevant and necessary to the dispute, they will not be discoverable under a discovery order, if they fall outside the “natural and ordinary meaning” of that order.

  1. Irish Airline Pilots Pension DAC v Mercer [Ireland] LTD T/A Mercer [2022] IEHC 22.
  2. Daly v Ardstone Capital Ltd [2020] IEHC 200.
  3. Analog Devices BV v Zurich Insurance Co [2005] 1 IR 274.

This document has been prepared by McCann FitzGerald LLP for general guidance only and should not be regarded as a substitute for professional advice. Such advice should always be taken before acting on any of the matters discussed.