It is draconian since it may be brought against someone who is only a potential defendant.
CPR31.16 establishes a threshold; whether the parties are likely to be parties to proceedings, whether the respondent would have had to give the disclosure were such a claim issued, and whether disclosure may assist in dispute resolution and reduce cost. If the applicant can satisfy these the court then considers the exercise of its discretion.
In ECU Group v HSBC and others  EWHC 3011 (Comm), HHJ Waksman noted that the jurisdictional threshold was not high, but the real question was the exercise of discretion which depends on the facts of the case. Underlying merit was one element of that exercise.
Roche Diagnostics v Mid Yorkshire Hospitals NHS Trust  EWHC 933 (TCC) found a failed procurement bidder contemplating a claim to challenge the fairness of the tendering process. Coulson J observed: “applications such as this must be decided by balancing, on the one hand, the claiming party’s lack of knowledge of what actually happened (and thus the importance of the prompt provision of all relevant information and documentation relating to that process) with, on the other, the need to guard against such an application being used simply as a fishing exercise…”.
However disclosure was not ordered in a recent tendering case CEMEX UK Ops v Network Rail  EWHC 2392 (TCC), given that the compromise of confidentiality was disproportionate where the claimant had enough information to plead. Similarly an application for early disclosure in a procurement claim was found to be misconceived and unnecessary in Gem Environmental Building Services v Tower Hamlets  EWHC 3045 (TCC).
ED&F Man v Obex Securities  EWHC 2965 (Ch) decided that a ‘claim’ includes an application under CPR6.2(c), such that the Court could order service of an application out of the jurisdiction.
The Court declined to order disclosure in Peel Port Shareholder Finance v Dornoch [2017 EWHC 865 (TCC) since there was specific legislation governing insurance claims that were relevant to that relationship.
In Howell v South London Church Fund (2017) unreported 27/07/17 (QB), HHJ Moloney QC considered an application for pre-action disclosure of an email by which the Fund had alerted a lettings agency that the proposed holiday letting of a property rented by Mr Howell was contrary to the terms of his tenancy. Although the Court granted the application as it would assist early resolution, it declined to grant an injunction against further defamatory remarks given the lack of underlying merit. Nevertheless the absence of merit was not fatal to the disclosure application.