part of the now well established three part test. See here for Customs & Excise v Barclays which authoritatively reviews the modern law.
Lord Bridge said,
‘In determining the existence and scope of the duty of care which one person may owe to another in the infinitely varied circumstances of human relationships there has for long been a tension between two different approaches. Traditionally the law finds the existence of the duty in different specific situations each exhibiting its own particular characteristics. In this way the law has identified a wide variety of duty situations, all falling within the ambit of the tort of negligence, but sufficiently distinct to require separate definition of the essential ingredients by which the existence of the duty is to be recognised.
Commenting upon the outcome of this traditional approach, Lord Atkin, in his seminal speech in Donoghue v. Stevenson  A.C. 562 , 579-580, observed:
‘The result is that the courts have been engaged upon an elaborate classification of duties as they exist in respect of property, whether real or personal, with further divisions as to ownership, occupation or control, and distinctions based on the particular relations of the one side or the other, whether manufacturer, salesman or landlord, customer, tenant, stranger, and so on. In this way it can be ascertained at any time whether the law recognises a duty, but only where the case can be referred to some particular species which has been examined and classified. and yet the duty which is common to all the cases where liability is established must logically be based upon some element common to the cases where it is found to exist.’
It is this last sentence which signifies the introduction of the more modern approach of seeking a single general principle which may be applied in all circumstances to determine the existence of a duty of care. Yet Lord Atkin himself sounds the appropriate note of caution by adding, at p. 580:
‘To seek a complete logical definition of the general principle is probably to go beyond the function of the judge, for the more general the definition the more likely it is to omit essentials or to introduce non-essentials.’
Lord Reid gave a large impetus to the modern approach in Dorset Yacht Co. Ltd. v. Home Office  A.C. 1004 , 1026-1027, where he said:
‘In later years there has been a steady trend towards regarding the law of negligence as depending on principle so that, when a new point emerges, one should ask not whether it is covered by authority but whether recognised principles apply to it. Donoghue v. Stevenson  A.C. 562 may be regarded as a milestone, and the well known passage in Lord Atkin’s speech should I think be regarded as a statement of principle. It is not to be treated as if it were a statutory definition. It will require qualification in new circumstances. But I think that the time has come when we can and should say that it ought to apply unless there is some justification or valid explanation for its exclusion.’
The most comprehensive attempt to articulate a single general principle is reached in the well known passage from the speech of Lord Wilberforce in Anns v. Merton London Borough Council …
But since the Anns case a series of decisions of the Privy Council and of your Lordships’ House, notably in judgments and speeches delivered by Lord Keith of Kinkel, have emphasised the inability of any single general principle to provide a practical test which can be applied to every situation to determine whether a duty of care is owed and, if so, what is its scope…
What emerges is that, in addition to
(a) the foreseeability of damage,
necessary ingredients in any situation giving rise to a duty of care are that
(b) there should exist between the party owing the duty and the party to whom it is owed a relationship characterised by the law as one of ‘proximity’ or ‘neighbourhood’ and that
(c) the situation should be one in which the court considers it fair, just and reasonable that the law should impose a duty of a given scope upon the one party for the benefit of the other.
But it is implicit in the passages referred to that the concepts of proximity and fairness embodied in these additional ingredients are not susceptible of any such precise definition as would be necessary to give them utility as practical tests, but amount in effect to little more than convenient labels to attach to the features of different specific situations which, on a detailed examination of all the circumstances, the law recognises pragmatically as giving rise to a duty of care of a given scope.
Whilst recognising, of course, the importance of the underlying general principles common to the whole field of negligence, I think the law has now moved in the direction of attaching greater significance to the more traditional categorisation of distinct and recognisable situations as guides to the existence, the scope and the limits of the varied duties of care which the law imposes.
We must now, I think, recognise the wisdom of the words of Brennan J. in the High Court of Australia in Sutherland Shire Council v. Heyman (1985) 60 A.L.R. 1 , 43-44, where he said:
‘It is preferable, in my view, that the law should develop novel categories of negligence incrementally and by analogy with established categories, rather than by a massive extension of a prima facie duty of care restrained only by indefinable ‘considerations which ought to negative, or to reduce or limit the scope of the duty or the class of person to whom it is owed.”
Edited, including (a) -(c) notation and paragraphing added, for ease of reading.