Held, appeal dismissed. There was no statutory obligation to obtain a further audit report. The Transport Act 2000 unambiguously identified the subject-matter of the audit report under section 123D, namely, an assessment of the scheme by the franchising authority under section 123B. Section 123D did not require the auditor to produce a report on some other document. Even if it were possible to carry out something in the nature of a section 123D audit on the COVID Impact Report, it could not be an audit report under section 123D. The statute made no provision for a fresh section 123B assessment, or for the revisitation of the original section 123B assessment, in the light of the provision of further information which might have a bearing on the conclusions reached by the authority in the assessment. Likewise, the statute contained no express requirement for the revisitation of the section 123B assessment or for a fresh assessment to be carried out if information came to light in the course of the public consultation which called into question the robustness or reliability of the information relied on in the original assessment. Indeed, there was nothing on the face of the statute that expressly obliged the authority to revisit its section 123B assessment if the audit report drew its attention to flaws in it, however serious those flaws might be. The absence of any express requirement to revisit the section 123B assessment at any time after it had been audited, was a major obstacle to construing the statute as providing for a fresh section 123D audit. The primary purpose of the statutory requirement of an audit under section 123D was to provide consultees with some independent quality assurance of the underlying information and the methodology used by the authority to assess it. That purpose was fulfilled when the audit was completed and sent out with the section 123B assessment and the consultation document. A secondary purpose was to draw to the attention of the authority any problems identified with the information or the methodology used in the assessment (something which the Franchising Guidance expressly obliged the auditor to do) so that, if need be, the authority could address them. That purpose was fulfilled when the authority received the audit report. If Parliament had intended to impose an obligation on an authority to commission a further audit in certain circumstances, the statute and the statutory guidance would not be silent on that topic. It might transpire that further information which was not taken into account was of such importance as to make it irrational for the authority to seek to go ahead with the proposed scheme without first considering the fresh information and, if need be, revisiting the assessment. But then it would be for the authority to decide how to address the situation. Parliament had not prescribed by statute what should happen in those circumstances. More broadly, the local authority had not acted irrationally in failing to commission a re-audit of the section 123B assessment. A further audit was one option, but not the only one rationally open to the local authority (paras 33–36, 46–56, 57, 59, 62–65, 67, 68).