AC-2024-LON-002644 - [2025] EWHC 2761 (Admin)

Prohibitive expensiveness Limb (b) is where likely costs are objectively unreasonable, having regard to six mandatory relevancies (CPR 46.27(3)(b)). What is Limb (b)? I think the answer is this. It is an objective standard, notwithstanding that the costs are actual costs incurred by the public authority and notwithstanding that they are real-world affordable for the actual claimant. The objective limit is not objective affordability. It is objective reasonableness. It is objective reasonableness to promote and secure access to environmental justice, with its public interest imperative. It is applicable to the contours and character of the parties, and the nature and implications of the proceedings. Hence the six prescribed mandatory relevancies (CPR 46.27(3)(b)).

It is vital to understand why there is a second limb. Limb (b) is not a second way to defeat a claimant for whom the proceedings are real-world unaffordable. Limb (b) is a second way to protect a claimant for whom the proceedings are real-world affordable. It arises if the first way has failed. Its premise is that there is real-world affordability. What this means is that, notwithstanding that the costs are the real costs of the actual case, and notwithstanding that the costs are within the claimant’s real-world affordability, they are still assessed as objectively unreasonable. It means there is a second question, after considering the claimant’s means. It starts with real-world unaffordability, but then turns to objective unreasonableness. These are the two, independent bases of prohibitive expensiveness.

If a Court were considering imposing a fine on an individual, the court might need first to be satisfied as to real-world affordability for that individual. This would be a question about means. You might decide that the fine is within the individual’s actual means. But you would then ask another question, about appropriateness and proportionality. That would be like a Limb (b).

Why is there this additional layer of protection, beyond real-world affordability? The answer is because we are talking about the importance of access to environmental justice with its accompanying public interest imperative. The costs caps are facilitatory. They are signalling an encouragement. That is because legal audits of public authority environmental decision-making promote a key public interest. At least in the case of paradigm environmental protection. So, that is the second key point: the application of Limb (b) is in the context of facilitating access to environmental justice with its accompanying public interest imperative. The approach is facilitative.

Limb (b) is not framed as a test of affordability. It is framed as a test of reasonableness. With its 6 mandatory relevancies, it looks at the situation of both parties, and the nature and implications of the case as an environmental judicial review. It thinks, deliberately, about what is needed by the environment (factor (iv)). That does not mean over-generosity. It does not mean anything goes. The situation of a claimant (factor (i)) can overlap with facts which also informed real-world affordability. A polluter resisting an environmental protection measure promoted by a public authority is likely to struggle to invoke objective unreasonableness for actual costs which are, for the claimant, real-world affordable. So is a wealthy landowner whose invocation of environmental protection happens to coincide with the protection of “extensive individual economic interests” (Edwards at §28ii). The situation of the defendant public authority (factor (i)) could involve its size and resources, or how its own environmental protection mission could be threatened. There are questions about importance, for the claimant and “for the environment” (factors (iii) and (iv)). There are questions of viability of the claim (factors (ii) and (vi)). There is a question of legal complexity (factor (v)). These are the features which inform whether there should be a shield from the real costs of litigation – albeit that they are real-world affordable for the claimant – by reference to what is an objectively reasonable measure of prohibitive expense, in the public interest world of environmental protection and legal audits of public authority decision-making.

When posing the questions for the CJEU in Edwards (see Case C-260/11 [2013] 1 WLR 2914 at §23), the domestic courts had been dealing with a standalone requirement of prohibitive expensiveness (see CJEU judgment at §25). The question as formulated reflected thinking about affordability. First, there was affordability on a so-called objective basis (“the ability of an ‘ordinary’ member of the public to meet the potential liability for costs”). Second, there was affordability on a so-called subjective basis (“the means of the particular claimant”). This thinking had been seen in earlier domestic case-law: see the Supreme Court judgment [2014] 1 WLR 55 at §12.

In response, the CJEU had described “the financial situation of the person concerned” (CJEU at §40; SC at §22). It had then said that real-world affordability (“solely”) was not enough. But the CJEU did not frame a second, objective requirement based on affordability, for ordinary members of the public or otherwise. It would have been very easy to do so. The Court spoke of costs which were not “objectively unreasonable”, which it directly linked by the CJEU to a public interest imperative where “members of the public and associations are … required to play an active role in defending the environment” (CJEU §40; SC §22).

In fact, even if this standard had been framed – whether by the CJEU or in Limb (b) – as a standard of “reasonable affordability”, it would still need to be approached understanding that it is intended to facilitate responsible and viable claims which invoke access to environmental justice, because of the accompanying public interest imperative, and especially in paradigm environmental protection cases.

Again, I do not think there is more, or less, to it than that. Again, I do not think any of what I have said is a gloss on the rules. I do not think any of is cumbersome or sophisticated. Again, I think it is very straightforward and easy to understand and apply. What I have said aligns most closely with the submissions of Mr Wolfe KC. That leaves two footnotes.

First, as to whether real-world affordability can feature within Limb (b), I think it can to a point. There is room for overlap, as Mr Luckhurst points out. As I have said already, the situation of a claimant (factor (i) in Limb (b)) can overlap with facts which also informed real-world affordability. The situation of the parties could, for example, include resources and access to third party funding which do more than show real-world affordability (Edwards §28ii). But what Limb (b) is not is a re-run of Limb (a). It cannot be the case that real-world affordability drives a conclusion of objective reasonableness. That would subvert the rule and undermine the public interest aims, as Mr Wolfe KC rightly points out.

The second footnote is about discretion and predictability. Limb (b) is described as an “objective” standard of unreasonableness. Its application is case-specific and context-specific. Limb (b) is sometimes described as a discretion. The word “may” in CPR 46.27(2). A careful reading of the rule appears to connote a possible residual discretion for refusing an upward variation even though it would not be prohibitively expensive (CPR 47.27(2)(a)), but no residual discretion for making any downward variation unless it is avoiding prohibitively expensive costs (CPR 47.27(2)(b)). I have put residual discretion to one side and focused in this case on prohibitive expensiveness. Prohibitive expensiveness is certainly an evaluative judgment, with room for appreciation and judicial latitude. I say this because open “discretion” can be an enemy of predictability and foreseeability. The greater the clarity, objectivity and predictability, the better.