21. […] A mere listing of evidentiary documents and witness statements as proof of Salahović [Prlić’ counsel]’s political activity does not […] suffice to establish prejudice to Prlić’s interests. The Prlić Appeal does not generally connect Salahović’s interests and activities to actual or potential conflicts of interest with his client. In particular, Prlić does not provide examples of how he was potentially or actually prejudiced by the alleged conflict of interest. He does not show any basis for a potential or actual risk that Salahović’s political and personal activities would “limit the choice of defence strategies”[1] in relation to Prlić’s case.

43.     […] Moreover, the Appeals Chamber notes that Article 14(D) of the Code of Conduct prohibits a representation with an adverse effect on either of the clients, regardless of whether they are represented in matters before the International Tribunal or other jurisdictions. […]

44.     […] While the said provision [Article 14(D) of the Code of Conduct] does not seem to distinguish between the duty of loyalty to a current and a former client,[1] the Appeals Chamber observes that a conflict of interest may be more difficult to discern when it arises from the context of successive or serial representation rather than concurrent representation. Parties made extensive references to national case-law and the Appeals Chamber finds it instructive to have a brief overview of underlying principles with respect to a counsel’s duty of loyalty to a former client in national jurisdictions.

45.     According to the relevant US and UK case-law on the matter, a conflict of interest vis-à-vis a former client exists when the subject matter of the two representations are substantially related so as to put at risk the confidences received from that client.[2] It is however important to note that such conflict of interest is considered to exist in all situations “when defense counsel is compelled to compromise his or her duty of loyalty or zealous advocacy to the accused by choosing between or blending the divergent or competing interests of a former or current client”.[3] Generally, it would be a case-by-case assessment by the judiciary of the character and extensiveness of the prior representation to ensure that the interests of both former and current clients are preserved.[4] In any case, doubts as to the existence of an asserted conflict of interest with respect to a former client should be resolved in favour of disqualification.[5]

46        As a general principle in French law, apart from confidentiality issues, a counsel can only accept a new representation in which he or she may be led to plead against a former client where such new case is entirely different from the previous one, so as to fully conform to his or her duty of loyalty.[6] Similar principles are provided for by the Code of Conduct for European Lawyers, according to which a lawyer “must […] refrain from acting for a new client if there is a risk of breach of a confidence entrusted to the lawyer by a former client or if the knowledge which the lawyer possesses of the affairs of the former client would give an undue advantage to the new client”.[1]

47      While the Croatian Attorney’s Code of Ethics is only explicit with respect to prohibiting legal assistance to an adverse party in a subsequent representation, it provides for duties of faithfulness and loyalty to a client which do not necessarily cease with the end of representation.[2] In Bosnia and Herzegovina, it is impermissible to represent clients with conflicting interests, and should such a conflict (or risk of infringing the confidentiality of information or the attorney’s independence) arise during litigation, the attorney has an obligation to return the power of attorney to all the parties involved.[3]

48      Having concluded that the simultaneous representation of the Appellant and Ademi by Prodanović and Sloković raises a high risk of a conflict of interest due to the fact that the Counsel would be limited in their choice of defence strategies in order to conform to their duty of loyalty,[4] the Appeals Chamber is of the view that, even if Prodanović and Sloković withdrew from Ademi’s defence, they would still be unable to represent the Appellant to the best of his interests as they would remain bound by their duty of loyalty to Ademi as a former client.[5] This potential conflict of interest is even more contoured considering the high probability that Ademi will be called as witness in the present case.[6]