66. The essential question is whether the act of terminating the tenancy is a private act. When considering how to characterise the nature of the act, it is in my view important to focus on the context in which the act occurs; the act cannot be considered in isolation simply asking whether it involves the exercise of a private law power or not. As Lord Mance observed in YL’s case [2008] AC 95 , both the source and nature of the activities need to be considered when deciding whether a function is public or not, and in my view the same approach is required when determining whether an act is a private act or not within the meaning of section 6(5). Indeed, the difficulty of distinguishing between acts and functions reinforces that conclusion.

67. In this case there are a number of features which in my judgment bring the act of terminating a social tenancy within the purview of the Human Rights Act 1998.

68. A useful starting point is to analyse the trust’s function of allocating and managing housing with respect to the four criteria identified by Lord Nicholls in the Aston Cantlow case [2004] 1 AC 546, para 12, reproduced above at para 35(5). First, there is a significant reliance on public finance; there is a substantial public subsidy which enables the trust to achieve its objectives. This does not involve, as in YL’s case, the payment of money by reference to specific services provided but significant capital payments designed to enable the trust to meet its publicly desirable objectives.

69 Second, although not directly taking the place of local government, the trust in its allocation of social housing operates in very close harmony with it, assisting it to achieve the authority’s statutory duties and objectives. In this context the allocation agreements play a particularly important role and in practice severely circumscribe the freedom of the trust to allocate properties. This is not simply the exercise of choice by the RSL but is the result of a statutory duty to co-operate. That link is reinforced by the extent to which there has been a voluntary transfer of housing stock from local authorities to RSLs.

70. Third, the provision of subsidised housing, as opposed to the provision of housing itself, is, in my opinion a function which can properly be described as governmental. Almost by definition it is the antithesis of a private commercial activity. The provision of subsidy to meet the needs of the poorer section of the community is typically, although not necessarily, a function which government provides. The trust, as one of the larger RSLs, makes a valuable contribution to achieving the government’s objectives of providing subsidised housing. For similar reasons it seems to me that it can properly be described as providing a public service of a nature described in the Lord Nicholls’s fourth factor.

71. Furthermore, these factors, which point in favour of treating its housing functions as public functions, are reinforced by the following considerations. First, the trust is acting in the public interest and has charitable objectives. I agree with the Divisional Court that this at least places it outside the traditional area of private commercial activity. Second, the regulation to which it is subjected is not designed simply to render its activities more transparent, or to ensure proper standards of performance in the public interest. Rather the regulations over such matters as rent and eviction are designed, at least in part, to ensure that the objectives of government policy with respect to this vulnerable group in society are achieved and that low cost housing is effectively provided to those in need of it. Moreover, it is intrusive regulation on various aspects of allocation and management, and even restricts the power to dispose of land and property.

72. None of these factors taken in isolation would suffice to make the functions of the provision of housing public functions, but I am satisfied that when considered cumulatively, they establish sufficient public flavour to bring the provision of social housing by this particular RSL within that concept. That is particularly so given that their Lordships have emphasised the need to give a broad and generous construction to the concept of a hybrid authority.

74. Those decisions certainly lend force to the argument that the character of the act is related to and may be defined by the source of the power being exercised. Where it is essentially contractual, so the argument goes, it necessarily involves the exercise of private rights.

75. In my judgment, that would be a misreading of those decisions. The observations about private acts in the Aston Cantlow case and YL’s case were in a context where it had already been determined that the function being exercised was not a public function. I do not consider that their Lordships would have reached the same conclusion if they had found that the nature of the functions in issue in those cases were public functions.

76. In my judgment, the act of termination is so bound up with the provision of social housing that once the latter is seen, in the context of this particular body, as the exercise of a public function, then acts which are necessarily involved in the regulation of the function must also be public acts. The grant of a tenancy and its subsequent termination are part and parcel of determining who should be allowed to take advantage of this public benefit. This is not an act which is purely incidental or supplementary to the principal function, such as contracting out the cleaning of the windows of the trust’s properties. That could readily be seen as a private function of a kind carried on by both public and private bodies. No doubt the termination of such a contract would be a private act (unless the body were a core public authority).

77. In my opinion, if an act were necessarily a private act because it involved the exercise of rights conferred by private law, that would significantly undermine the protection which Parliament intended to afford to potential victims of hybrid authorities. Public bodies necessarily fulfil their functions by entering into contractual arrangements. It would severely limit the significance of identifying certain bodies as hybrid authorities if the fact that the act under consideration was a contractual act meant that it was a private act falling within section 6(5).

83. Both the Aston Cantlow case [2004] 1 AC 546 and YL’s case [2008] AC 95 emphasised that it does not necessarily follow that because a body is a public body for the purposes of section 6, it is therefore subject to public law principles. The Divisional Court held, however, that in this case the two questions had to be determined the same way. Mr Arden does not now seek to contend otherwise. In my judgment, he was right not to do so.