Held, (1) Defamation claims were no different from any other claims in tort or delict for which article 5(3) of the Lugano Convention provided a range of jurisdictional options (place of domicile; place where harmful event occurred; and place where damage was directly suffered). There was no authority which suggested that article 27 was inapplicable to such claims, and no sound reason for restricting its applicability. On the contrary, the avoidance of parallel proceedings and risk of irreconcilable judgments which article 27 was designed to avoid dictated that it should apply. Any argument that the use of a claim for negative declaratory relief was abusive if it restricted the choice of forum available to a claimant under article 5(3) of the Lugano Convention proceeded from a false premise. There was no such abuse. Negative declaratory relief claims were entirely legitimate and in any tort claim in which article 5(3) conferred a choice of jurisdiction on the claimant for a global claim, the choice was equally conferred on a defendant by way of a negative declaratory relief claim; in each case the option was circumscribed by the simple and automatic mechanism in article 27 of who started first. That was not an abuse of the regime established by the Convention, but rather its implementation (paras 99, 101, 105, 106).

(2) Appeal allowed in part (Popplewell LJ dissenting). The provisions of articles 27 and 28 of the Lugano Convention drew a clear and important distinction between “proceedings involving the same cause of action and between the same parties”, in the former, and “related actions”, in the latter. The former was narrow and mandated that the court “shall decline jurisdiction”. The latter was broad and, by paragraph (1), gave the court a discretion to grant a stay. Article 27 had a simple test. All the court had to determine was whether the proceedings involved “the same cause of action and [are] between the same parties”. There was no need to consider, as there was under article 28, whether the actions were “so closely related that it is expedient to hear and determine them together to avoid the risk of irreconcilable judgments”. The risk of irreconcilable judgments was not referred to in article 27 because that risk, if article 27 applied, was self-evident. As a matter of domestic law, if a court decided that the causes of action were the same, it would seem inevitable, that cause of action estoppel would apply. There was, therefore, no reason to apply article 27 broadly to avoid the risk of irreconcilable judgments because article 28 was itself a broad, or at least a broader, provision. Furthermore, there was good reason to confine article 27 to its terms because of the potential effect of its application. The structure of the provisions supported the conclusion that the test in article 27 was intended to be a closely defined one which did not require any extensive inquiry but simply the determination of whether proceedings had the same cause of action and the same object. There was a clear distinction in the authorities between the approach to the question of whether proceedings had the same cause to that of whether they had the same object. It was, therefore, important to apply what was said about each only to the relevant element. Proceedings would have the same cause of action if they were in identical terms or two sides of the same coin; and article 27 was not engaged merely by virtue of the fact that common issues might arise. In contrast, whether proceedings had the same object was a broader analysis and depended on whether the question at the heart of the two actions was the same. It was in that context that claims did not have to be entirely identical; it depended on whether the end the action had in view was the same and whether the same issue was central to both actions. Differences in the form of the pleadings (one positive and one negative) and the differences in the remedy sought (damages and a non-liability declaration) did not make the object of the dispute different. It was incorrect to propose that the approach should be to search for the common issues which captured the essential nature of the cause of action in the sense of its main or central focus. That was an approach which resonated with the question of whether the proceedings had the same object or subject matter and not that of whether they had the same cause, and would have the effect of removing any real substance from the specific requirement that the proceedings had the same cause as well as the same object. In the present case article 27 did not apply because, whilst the proceedings in Norway and the proceedings in England might have the same object (namely determination of liability for the tweet and for damages/negative declaratory relief), they did not involve the same cause of action. The legal principles involved in the Norwegian proceedings did not mirror the legal principles involved in the English proceedings such that they were legally irreconcilable; the juridical basis of the proceedings was not the same. Accordingly, the judge had erred in his conclusion that article 27 applied to defeat the claimant’s defamation claim (paras 105, 106, 113, 115–118, 128, 161–164, 167, 173, 175–176).