Mahmudov & Anor v Sanzberro & Ors  EWHC 3433 (QB) tackles the issue of libel tourism. As Collins Rice J puts it 
underlying the contest of law is a contest of two mainstream policies embodied in modern defamation law: on the one hand, the need for the law to keep up with the borderless realities of the internet, and on the other the need for international libel to be dealt with by the courts best able fairly to do so (or, to put it less neutrally, to prevent ‘libel tourism’).
The case is held under Brussels Ia for the claim was introduced on 31 December 2020, ‘IP completion day’. Parties mostly seem at loggerheads over the implications of CJEU C-509/09 eDate. Claimants suggest eDate establishes a stand-alone full jurisdictional gateway for the Member State where the aggrieved has his or its centre of interests – CoI. Defendant claims 
there is still a binary choice, as per Shevill: to sue either (a) where a defendant is domiciled or (b) where a completed tort (the harmful event) occurred. The effect of eDate, they say, is that claimants taking the second route in their CoI country can now get global relief rather than being limited to compensation for harm arising in that individual state. CoI is not jurisdictional in the pure sense of introducing a freestanding basis for bringing an action somewhere; it is jurisdictional only to the limited or secondary (but nevertheless important) extent of the nature and quantum of the relief that may be sought.
Parties oddly seem in agreement that Shevill v Presse Alliance (No.2)  AC 959 reaffirmed ( in Mahumdov]
that what constituted the ‘harmful event’ was to be determined by the national court applying its own substantive law. In other words, the preliminary jurisdictional question for the High Court in a libel case brought against a non-domiciled defendant was whether a claimant could show to the requisite standard that all the components of a tort actionable in the UK were present
I find that debatable to say the least, and in fact that consensus has an important impact on the judge’s final conclusion, which rejects CoI as a stand-alone gateway:  the judge sides with the defendants for the claimant’s reading would imply ‘an autonomous meaning of the ‘place where the harmful event occurred’ ‘. The latter, many might argue, must be the implication of the CJEU’s overall application of Brussels Ia. At  Napag Trading is offered in support however the judge I feel in Mahmudov should have made a clearer distinction (as the judge did in Napag Trading) between the EU-governed jurisdictional gateway for tort, and the (England and Wales) governed Civil Procedure Rules test for a ‘good arguable case’. As I note in my review of Napag Trading, these CPR rules may still form a formidable procedural hurdle, however properly distinguishing between them is important, among others for costs reasons.