In  British Telecommunications Plc v Office Of Communications [2017] CAT 25 the Competition Appeal Tribunal commented on two of the central evidential issues of much commercial litigation: witnesses who give much commentary and “argue” the case; experts who act as advocates.  This approach does not assist in any kind of litigation.

“… statements should in general only contain evidence that the witness would be allowed to give orally, and witnesses should not engage in matters of argument:”


The Tribunal was considering issues relating to the regulation of leased lines. BT was appealing against certain rulings by Ofcom.


“…we wish to place on record two general points regarding the evidence.

  1. The first is that we were not remotely assisted by the length and tone of much of the written evidence and expert reports with which we were assailed.  Whilst we appreciate that Ofcom’s Final Statement was itself a vast document, and the issues with which it deals are complex, we thought that much of the written material, in particular from BT, was excessively prolix and argumentative.  At times, that written material also sought to reopen old (and irrelevant) battles.  This style of written statement inevitably tended to obscure rather than enlighten, and led to cross-examination which strayed into argument.

  2. In saying this, we appreciate that the regulatory environment of the BCMR cycle is very different from the situation that prevails in ordinary commercial litigation.  The questions to be answered necessarily concern looking into the future rather than simply looking at events that have happened in the past.  Moreover, the personnel who give evidence are very likely to have been closely involved on behalf of their employer over several cycles of consultation and the litigation that appears inevitably to follow a regulatory decision in the telecommunications field.  This may make it very difficult for such witnesses to distinguish between the submissions that they have been involved in preparing or receiving during the BCMR process, and the relevant factual evidence that they have to give on an appeal.

  3. That said, in principle there should be no difference in the content of witness statements of fact used in the Tribunal proceedings and those used in ordinary commercial litigation.  Such statements should in general only contain evidence that the witness would be allowed to give orally, and witnesses should not engage in matters of argument: see JD Wetherspoon plc v Harris [2013] 1 WLR 3296 and words to similar effect at paragraph 7.61 of The Tribunal’s Guide to Proceedings 2015.

  4. The second point arises from the comments which we have made regarding the evidence of Dr. Basalisco and Ms. Curry.  As Cresswell J made clear in The Ikarian Reefer [1993] 2 Loyds Rep 68 at 81-82, an expert witness in civil proceedings should provide independent assistance to the court by way of objective unbiased opinion in relation to matters within his or her expertise, and should never assume the role of an advocate. 

  5. Those requirements are reflected in paragraph 11 of CPR Practice Direction 35, which states:

“Experts must provide opinions that are independent, regardless of the pressures of litigation.  A useful test of ‘independence’ is that the expert would express the same opinion if given the same instructions by another party.  Experts should not take it upon themselves to promote the point of view of the party instructing them or engage in the role of advocates.”

  1. To similar effect is paragraph 7.67 in The Tribunal’s Guide to Proceedings 2015, which states:

“[…] Expert evidence presented to the Tribunal should be, and should be seen to be, the independent product of the expert uninfluenced by the pressures of the proceedings.  An expert witness should never assume the role of an advocate […].”

  1. As regards Ms. Curry’s position, we note that in Field v Leeds CC [2000] 32 HLR 618 the Court of Appeal accepted in principle that provided that the court was satisfied that a witness was properly qualified to act as an expert, and that the party calling him could show that the witness had full knowledge of the need for objectivity, the mere fact that the witness was employed by one of the parties to proceedings would not prevent him from giving expert evidence.  But those observations were simply made as a matter of principle and certainly did not establish that it will always be appropriate for an employed person to give expert evidence for his employer.  It is also significant that the case concerned a tenant’s occupation of public housing owned by a local authority.  They were not proceedings based on any decision in which the very employee who was proferred as expert had played a significant role.

  2. Our attention was also drawn to a number of decisions of the Tribunal in cases where witnesses employed by Ofcom in similar positions to Ms. Curry had given expert evidence which the tribunal had found satisfactory.  These included, for example, British Telecommunications Plc v Ofcom (Ethernet Determinations) [2014] CAT 14.  At [72], the Tribunal held:

“Ofcom called only one witness, Mr Geoffrey Myers, who is Director of Competition Economics at Ofcom and also a Visiting Professor in Regulation at the London School of Economics. Mr Myers was responsible for overseeing the economic analysis in the Determination, and to that extent his evidence was in part as a witness of fact. He was also involved in the leased lines market review, which led to the 2004 LLMR, but not in the market reviews that led to the 2008 BCMR and 2009 LLCC. In addition, however, Mr Myers gave evidence also as an expert economist. It was put to him that he was appearing as the “champion of Ofcom” to defend the Determination but Mr Myers denied this and said that he was very conscious of his duty to the Tribunal. We accept that answer and do not find that the fact that he was employed by Ofcom impeded his objectivity.”

  1. Ultimately these cases prove no more than that the Tribunal in question was satisfied as to the particular individual’s ability to give objective expert testimony in the circumstances of the case.  For the reasons we have identified, however, at times we found it difficult to distinguish the nature of Ms. Curry’s evidence in this case.  We therefore do not think that cases such as Field v Leeds CC and Ethernet Determinations should be taken as precedents which in any way lessen the obvious difficulties faced by any person responsible for a regulatory decision being asked to give both factual evidence and expert evidence in relation to that very decision.