They claimed compensation for personal injury, property damage, loss of income, amenity and enjoyment of land because of copper mine discharges.

By an order dated 16 June 2016, issued following judgment on 27 May 2016, Peter Coulson,[4] then a High Court judge, granted jurisdiction over the claims:[5] the case could not be fairly pursued in Zambia.

Former employees were more likely to succeed, but residents have an arguable case, both in English and Zambian law, considering Erste Group Bank AG (London) v JSC (VMZ Red October).

Paragraph 79 alleges that Vedanta's duty of care arose as a result of their assumption of responsibility "for ensuring that [KCM]'s mining operations do not cause harm to the environment or local communities, as evidenced by the very high level of control and direction that [Vedanta] exercise at all material times over the mining operations of [KCM] and its compliance with applicable health, safety and environmental standards."

It is Vedanta's case that, on a proper analysis, the tortious claim advanced by reference to Chandler v Cape is either unarguable or is so weak that the court should take that into account when exercising its discretion against allowing the claimants to serve out of the jurisdiction.

They point to the fact that, in the one area where this principle was doubted, namely where there were pending proceedings in another Member State, any uncertainty has been resolved by subsequent Regulations.

In addition they argue that, even if the court was tempted to, it would be wrong in principle to impose a stay for case management reasons, because that would be achieving by the back door that which Owusu expressly prohibits at the front.

... on the face of the pleading, there is a real issue to be tried between the claimants and Vedanta and that, whilst establishing their claims may not be straightforward, they are quite entitled to try and bring themselves within the class of liability recognised in Caparo v Dickman and Chandler v Cape.

Thus I would be wrong to ignore the possibility that, if the litigation was conducted in Zambia, Vedanta/KCM could seek to strike it out, or if they lost at trial, Vedanta might put KCM into liquidation in order to avoid paying out to the claimants.

And the evidence in the public domain, summarised in Mr Day's fifth witness statement at paragraphs 121-126, indicates that KCM were in 2014 running at a significant loss.

The defendants, who originally suggested that legal aid would be available, backtracked, and the highest they could put it at the hearing was that there was the possibility that the claimants could obtain exceptional funding.

He is emphatic in his view that the Legal Aid Board would not have the capacity or funding to commence an action in a large environmental claim on behalf of 1,800 claimants.

On the other, the court cannot ignore reasonable grounds which may be disclosed at the summary judgment stage for believing that a fuller investigation of the facts may add to or alter the evidence relevant to the issue: see Tesco Stores Ltd v Mastercard Inc [2015] EWHC 1145, per Asplin J at para 73.

46 The main thrust of the appellants' case under this heading was that a conclusion that Vedanta had incurred a duty of care to the claimants would involve a novel and controversial extension of the boundaries of the tort of negligence, beyond any established category, calling for a cautious incremental approach by analogy with established categories, which therefore required a detailed investigation of the claimants' case, which neither the judge nor the Court of Appeal carried out.

48 It might be thought that an assertion that the claim against Vedanta raised a novel and controversial issue in the common law of negligence made it inherently unsuitable for summary determination.

Everything depends on the extent to which, and the way in which, the parent availed itself of the opportunity to take over, intervene in, control, supervise or advise the management of the relevant operations (including land use) of the subsidiary.

50 Mr Gibson and Mr Hermer were eventually ad idem in commending to the court the pithy and in my view correct summary of this point by Sales LJ in AAA v Unilever plc [2018] EWCA Civ 1532 , para 36: "There is no special doctrine in the law of tort of legal responsibility on the part of a parent company in relation to the activities of its subsidiary, vis-à-vis persons affected by those activities.

Helpful guidance as to relevant considerations was given in Chandler v Cape plc; but that case did not lay down a separate test, distinct from general principle, for the imposition of a duty of care in relation to a parent company.

For my part, I would be reluctant to seek to shoehorn all cases of the parent's liability into specific categories of that kind, helpful though they will no doubt often be for the purposes of analysis.

52 Mr Gibson sought to extract from the Unilever case and from HRH Emere Godwin Bebe Okpabi v Royal Dutch Shell plc [2018] EWCA Civ 191; [2018] Bus LR 1022, a general principle that a parent could never incur a duty of care in respect of the activities of a particular subsidiary merely by laying down group-wide policies and guidelines, and expecting the management of each subsidiary to comply with them.

Group guidelines about minimising the environmental impact of inherently dangerous activities, such as mining, may be shown to contain systemic errors which, when implemented as of course by a particular subsidiary, then cause harm to third parties.

53 Even where group-wide policies do not of themselves give rise to such a duty of care to third parties, they may do so if the parent does not merely proclaim them, but takes active steps, by training, supervision and enforcement, to see that they are implemented by relevant subsidiaries.

Similarly, it seems to me that the parent may incur the relevant responsibility to third parties if, in published materials, it holds itself out as exercising that degree of supervision and control of its subsidiaries, even if it does not in fact do so.

54 Once it is recognised that, for these purposes, there is nothing special or conclusive about the bare parent/subsidiary relationship, it is apparent that the general principles which determine whether A owes a duty of care to C in respect of the harmful activities of B are not novel at all.

They may easily be traced back as far as the decision of the House of Lords in Dorset Yacht Co Ltd v Home Office [1970] AC 1004, in which the negligent discharge by the Home Office of its responsibility to supervise Borstal boys working on Brownsea Island in Poole Harbour led to seven of them escaping and causing serious damage to moored yachts in the vicinity, including one owned by the plaintiff.

Secondly, he accepted the invitation of counsel on both sides to treat Caparo Industries plc v Dickman [1990] 2 AC 605 , and its three ingredients of foreseeability, proximity and reasonableness, as the starting point.

This assumed, contrary to my view, that he was dealing with a novel category of common law negligence liability, but he can hardly be criticised for having done so in the light of the parties' joint invitation.

At para 119 he said this: "In the light of that view, it is unnecessary for me to identify in any detail the evidence [on] which the claimants rely in support of their case that Vedanta, as the parent company, owed a relevant duty of care.

For the reasons I have already given, his legal analysis may have departed slightly from the ideal, but only in respects in which either he followed the parties' joint invitation, or by imposing a straitjacket derived from the Chandler case which, if anything, increased rather than reduced the claimants' burden in demonstrating a triable issue.

For my part, if conducting the analysis afresh, I might have been less persuaded than were either the judge or the Court of Appeal by the management services agreement between the appellants, or by the evidence of Mr Kakengela.