[2025] EWHC 1160 (TCC)

Unsurprisingly, there is no dispute between the parties as to the general applicability and content of the American Cyanamid principles.

However, Avanti contends that although phrased in negative terms, the injunction sought here is in reality a mandatory injunction to compel it to keep on performing its services for EE until trial or further order. That being so, and in relation to the merits threshold to be satisfied on an application for an interlocutory injunction, the appropriate test is not the usual “serious issue to be tried” but rather the higher standard of the applicant being able to show with a “high degree of assurance” that it is likely to be held entitled to the injunction at trial.

In this context, Avanti relies upon dicta from cases such as Films Rover International Ltd v. Cannon Film Sales Ltd [1987] 1 WLR 670, at 680-681, Harmony Innovation Shipping PTE Ltd v. Caravel Shipping Inc [2019] EWHC 1037 (Comm) and Harvey v Santander UK Plc [2023] EWHC 2947.

For its part, EE responds that in this case, there is no basis for a higher merits threshold. It relies in particular on the opinion of Lord Hoffmann in the Privy Council decision in National Commercial Bank Jamaica Ltd v Olint Corpn Ltd [2009] UKPC 16 at paragraphs 18-21. At paragraph 20 he disavowed the “box-ticking” exercise undertaken by the courts below whereby if the injunction was prohibitory the test was “serious issue to be tried”, whereas if it was mandatory the test was a “high degree of assurance”. The position was more nuanced than that, as the following passage from paragraph 19 made clear:

“What is true is that the features which ordinarily justify describing an injunction as mandatory are often more likely to cause irremediable prejudice than in cases in which a defendant is merely prevented from taking or continuing with some course of action: see Films Rover International Ltd v Cannon Film Sales Ltd [1987] 1 WLR 670, 680. But this is no more than a generalisation. What is required in each case is to examine what on the particular facts of the case the consequences of granting or withholding of the injunction is likely to be. If it appears that the injunction is likely to cause irremediable prejudice to the defendant, a court may be reluctant to grant it unless satisfied that the chances that it will turn out to have been wrongly granted are low; that is to say, that the court will feel, as Megarry J said in Shepherd Homes Ltd v Sandham [1971] Ch 340, 351, a high degree of assurance that at the trial it will appear that the injunction was rightly granted.”

EE also points out that here, while Avanti would be compelled to continue to provide its services to EE, it would not be unduly burdensome or difficult for it to do so in and of itself, as it has been doing so since 2016. This is a far cry from a mandatory injunction requiring a property owner, for example, to demolish or indeed erect a substantial structure, or provide services to a party or do acts which would then be likely to require policing.

In my judgement, in this case, it would be undesirable for the court to choose between the two merits threshold tests where the essence of the issue is a point of construction and a relatively short one at that, in my view.

Accordingly, I shall apply the usual “serious issue to be tried” test. I should add that this is not the sort of case where the underlying merits turn or turn significantly on disputed questions of fact where it might be relatively easy to surmount this threshold or where, indeed, the defendant is prepared to accept that the threshold is met and concentrates rather on the balance of convenience. Here, as already noted, the issue is one of contractual construction where Avanti contends that EE’s claimed construction is plainly wrong and cannot therefore give rise even to a serious issue to be tried.

I now turn to that matter.