The Parliamentary expenses scandal gave rise to a constitutional issue concerning the scope of Parliamentary privilege. The defendants contended that by reason of privilege and article IX of the Bill of Rights 1689, the criminal courts had no jurisdiction to examine Parliamentary expenses claims. Led by Lord Pannick QC, Louis Mably appeared for the Crown in the Court of Appeal and the Supreme Court. Both appellate courts rejected the defendants’ contention, and found that there was no constitutional bar to the prosecution. Louis then went on to represent the Crown in the substantive criminal proceedings.