At the heart of all professional codes is some sense of shared ethical values. In UK legal education and practice, exactly what that shared understanding is has remained somewhat inchoate. Perhaps not for much longer, if the IBA recommendation that bar associations and societies around the world "take affirmative steps" to implement the Guiding Principles on business and human rights in local legal practice is adopted. As @RichardMoorhead points out, any or all of national law, conventional business practice and indeed client demands may conflict with a formal commitment by law firms to prevent, mitigate or remediate human rights risks in legal practice. An overly robust cross-examination of a vulnerable witness, or a spot of witness statement polishing may create an ethical basis for complaint against a lawyer even if in each case the lawyer in question can rightly claim that he or she was acting with integrity, in his client's best interests, and in all other respects in accordance with his professional duties. The recent history of legal regulation is littered with examples of law firms in this jurisdiction getting such ethical calls wrong: see for instance: http://www.sra.org.uk/sra/news/press/davenport-lyons.page. The assertion that the client's interests demand such an aggressive approach to litigation or putative litigation will no longer wash, even if it ever did. If the Law Society/SRA takes up the IBA's call, there may be (for the first time) an explict ethical, rather than legal, code underpinning this belief.
The reach of the guidance goes beyond advice to clients though. Particularly of note is the warning that: a company’s litigation strategy and tactics has recently been raised as a topic to explore under the responsibility to respect human rights. As Professor Ruggie has said, business lawyers may wish to consider ‘laying out for their client the entire range of risks entailed by the litigation strategy and tactics, including concern for their client’s commitments, reputation, and the collateral damage to a wide range of third parties’ as part of helping their client understand the full implications of any proposed approach to responding to claims of human rights harms. It seems to me that there is a plausible argument that lawyers will need to consider the implications not just for the client’s risk but also for their own conduct risk.