IP-2023-000104 - [2024] EWHC 233 (IPEC)

The parties adopted the usual principles set out by Lord Diplock in American Cyanamid Co v Ethicon Ltd [1975] AC 396. The most important of these are (here stated on the assumption that, as in American Cyanamid, it is the claimant applying for the interim injunction):

The defendants submitted that Lord Diplock recognised in American Cyanamid that maintaining the status quo is often the safest course. I do not think that is an accurate characterisation of what Lord Diplock said. He did refer to the status quo as something that could be taken into account, but only if the factors I have numbered (ii) to (iv) above result in an even balance. It is also my impression that in the very many cases following American Cyanamid, only rarely has the grant of an interim injunction depended on the status quo.

I have already decided that there is a serious question to be tried. As sometimes happens, the parties drew no real distinction between the balance of irreparable harm and the balance of convenience. So assuming that the defendants would suffer at least some irremediable damage if no injunction were to be granted, the issue boils down to that stated by Lord Hoffmann in National Commercial Bank Jamaica Ltd v Olint Corpn Ltd (Jamaica) [2009] UKPC 16 at [17]:

“The basic principle is that the court should take whichever course seems likely to cause the least irremediable prejudice to one party or the other.”