"No party may call an expert or put in evidence an expert's report without the court's permission."
"[20] In summary, I consider that the authorities demonstrate that, where the issues are concerned with manifest error or unfairness, expert evidence will not generally be admissible or relevant in judicial review or procurement cases. That is in part because the court is carrying out a limited review of the decision reached by the relevant public body and is not substituting its own view for that previously reached; in part because the public body is likely either to be made up of experts or will have taken expert advice itself in reaching the decision; and in part because such evidence may usurp the court's function. [21] All of that said, however, I believe that it goes too far to say that expert evidence can never be admissible in public procurement cases concerned with manifest error. In some cases, it may be required by way of technical explanatory evidence ( Lynch ). In addition, there may be other cases where, unusually, such evidence is both relevant and necessary to allow the court to reach a conclusion on manifest error. That may be particularly so where the particular issue is specific and discrete, such as a debate about one of the criteria used in the evaluation ( Henry Bros ) or complex issues of causation ( Harmon ). Thus, I do not accept the submission, trailed at one point in Mr Giffin's skeleton argument, that, if expert evidence is required to support an allegation of manifest error, that would of itself indicate that the error could not be manifest. In my view, that would always depend on the facts of the particular case. [22] Having concluded that expert evidence is not generally admissible in a case of this type, but that there may be unusual circumstances which justify the use of experts, I turn to the particular facts of this case. Is this a claim where the technical background is so complex that explanatory expert evidence is required, and/or is this an unusual case where expert evidence on some or all aspects of the tender evaluation process is required in order to allow the court to reach a proper view on the issues of manifest error or unfairness?"