In R (on the application of Prudential plc and another) (Appellants) v Special Commissioner of Income Tax and another (Respondents) [2013] UKSC 1, the majority (5:2) held that LPP should not be extended to communications in connection with advice given by professional people other than lawyers, even where that advice is legal advice.

Extending LPP would bring uncertainty to a clear and well understood principle and raise questions of policy which should be left to Parliament, the judges said.

The Bar Council intervened in the case, represented on a pro bono basis by Field Fisher Waterhouse, and counsel Bankim Thanki QC, Ben Valentine and Henry King. The Bar Council argued that extending LPP would undermine the necessary absolute confidentiality agreement between lawyers and clients, create uncertainty around the established scope of LPP, and constitute a significant inroad into the principle, necessary for the sound administration of justice, that relevant material should be placed before the court.