On 28 September 2012 the High Court rejected an application under which claimants sought permission to adduce expert evidence at the trial of a public procurement dispute under the Public Contracts Regulations 2006 (as amended), with Eversheds LLP acting for the successful respondent (see BY Development Ltd and others v Covent Garden Market Authority [2012] EWHC 2546 (TCC)).  This decision is a useful review of the principles and limited circumstances in which expert evidence is admissible in procurement challenges.


The claimants, as unsuccessful bidders, brought a challenge against a decision by the Covent Garden Market Authority ("the Authority") to award a development contract for New Covent Garden Market to a rival bidder.  The claimants alleged that the Authority made manifest errors in its assessment of the bids, particularly in relation to planning matters and financing.  The claimants also alleged that their bid was treated unfairly and there was unequal treatment by the Authority, which the Authority denied.

The claimants applied to the High Court for permission to rely on expert evidence in relation to certain planning and finance issues.  The Authority submitted that such expert evidence was neither admissible nor relevant.


The High Court concluded that the issues raised in public procurement disputes are akin to judicial review cases in that they are concerned with manifest error or unfairness so, as a general rule, expert evidence will not be admissible or relevant.

The rationale behind the Court's ruling is that:

  • the function of the court is limited to a review of the contracting authority's decision, solely to determine whether there was manifest error (very similar to the Wednesbury test of irrationality in judicial review proceedings) and/or whether the tender process was unfair;
  • the court's role is not to substitute its own view on the merits (or otherwise) of rival bids for that of the contracting authority;
  • the contracting authority is likely to be either made up of experts, or to have taken advice from such experts; and
  • such expert evidence may usurp the court's function.

Accordingly, as with judicial review cases, expert evidence in procurement cases will not generally be admissible, save in "unusual circumstances".  Consequently, expert evidence may be admissible where it is required to provide technical explanations on particularly complex points, the applicability of evaluation criteria (rather than the marks that should have been awarded) or causation, where such evidence is relevant and necessary to allow the court to reach a conclusion.

In relation to the claim of unequal treatment/unfairness (rather than manifest error), the Court considered that it was difficult to see any circumstances in which expert evidence would be admissible in procurement cases.


This decision means that claimants will not be allowed to revisit the entire evaluation process, with experts picking through all of the detail with a fine tooth comb, in an attempt to aggregate minor errors in order to build an overall case against the contracting authority.  The decision is therefore likely to strengthen the position of a contracting authority that is seeking to resist a procurement challenge.