At the judicial review hearing in February 2025, brought by the Borough Council, the High Court concluded that the correct purposive construction of S.2(1)(i) of the 2017 Act is to authorise the works comprised in HS2’s application, by virtue of falling within the Act limits and being “necessary and expedient”. Thus, the works benefit from deemed planning permission under the HS2 Act. The judicial review claim was dismissed by the judge, with all three grounds of judicial review (concerning illegality and procedural impropriety) held to be unsupportable.

Mr Justice Dove held that the defendants properly understood the law which they were applying, and ‘reached a conclusion in respect of evaluative judgment that cannot be impugned.’ It was recognised that the project authorised by the 2017 Act could not have every detail identified and fixed in advance but would require flexibility as to its final form. The legislation clearly provided for circumstances in which there would be other works pursuant to section 2(1) of the 2017 Act, which could not be specified in advance. Mr Dove applied the principles established in <em>R v Rochdale Borough Council ex parte Milne [2001] Env. LR22</em>, thereby concluding: ‘works will be within the scope of the project which had been the subject of Environmental Impact Assessment if they would not give rise to any likely <em>significant effects</em> greater than those which had been assessed in the environmental statement.’

Concluding that the defendants directed themselves correctly on statutory construction and thus on the question of deemed planning permission, the judge stated, ‘the issue of whether or not there were new or different likely significant effects,’ resulting from the works, ‘were matters for the evaluative judgment of the defendants based on the evidence before them’. Crucially, the defendants’ reasons, including the application of their understanding of the statutory regime, were considered ‘perfectly adequate’. He stated that regardless of the adequacy of the stated reasons, ‘the answer that the defendants would have given would be the same.’