Groundless threats before the grant of the patentPrint publication
Section 70(1) of the Patents Act 1977 states “where a person (whether or not the proprietor of, or entitled to any right in, a patent) by circulars, advertisements or otherwise threatens another person with proceedings for any infringement of a patent, a person aggrieved by the threats (whether or not he is the person to whom the threats are made) may … bring proceedings in the court against the person making the threats …”.
A claim cannot be brought if the threat is not “groundless”. Therefore if the maker of the threat can prove that there has been or will be an infringement of his patent rights, the party threatened will have no cause of action.
In Global Flood Defence Systems Ltd & Another v Van Den Noort Innovations BV & Others  the patent the subject of the threats had not yet been granted. It was still at the application stage. Nonetheless the defendants put notices on their website alleging patent infringement and wrote a letter to a third party complaining that their patent was being infringed. The claimant argued that this constituted a groundless threat; the defendant raised a defence of justification under section 70(2A) of the 1977 Act. The claimant sought summary judgment.
The defendants relied on section 69 of the 1977 Act, which provides that the rights granted by a patent are backdated to the date of grant and that, whilst they did not currently have a patent, they might have one by the time of the trial.
Hacon J in the IPEC held that it was indeed plausible that the defendants would have a patent by the time of trial and that they would be able to rely on the defence of justification if they succeeded in getting the patent by the time of the trial. Accordingly, the summary judgment application was refused. At trial, to invoke the defence of justification successfully, the defendants would need to show, first, that the patent was granted and, secondly, that the claimant’s acts would have infringed the patent had it been granted on the date the patent application was granted.
The fact that some of the threats included reference to patent rights that did not yet exist did not mean the defence of justification could not succeed.
  EWHC 153 (IPEC)