Who, for the purposes of a duty to consult before making a decision, is involved in or “affected by” a proposal? This was considered by Kerr J in R ( RDAG ) v Neath Port Talbot CBC (2022) 2674 (Admin). It is primarily an “evaluative factual judgment” to be made by the decision-maker: para 107. It is not for the Court to interfere with that judgment unless the authority misdirects itself or otherwise errs on established public law principles. The authority must, however, direct itself in accordance with the true meaning of “affected” when that concept is relevant. In those circumstances the meaning is for the Court tom determine, objectively.
There is an affect by a proposal if there may be a “material change” because of the proposal. Then that potential for change needs to be addressed: para 109.
A “real possibility” of there being a material change is enough for there to be an affect, because, if the possibility exists, it must be dealt with: para 110. The need to address the possible impact of a proposal is an effect. The likelihood of change does not have to be a certainty. It does not have to be a very strong likelihood. A real possibility is enough. That is because the possibility must be addressed. A possibility cannot be ignored, even if, as it turns out, the change does not materialise.
So-called “mitigation measures” are unlikely to form a proper basis for a judgment that there is not an effect: para 111. Real mitigation measures point towards an effect from the proposal, not the contrary conclusion: paras 112- 115 inclusive.