The Upper Tribunal has rejected an attempt to put a report by an unofficial grouping of MPs into evidence in an English language testing appeal. The case is DK and RK (Parliamentary privilege; evidence) India  UKUT 61 (IAC) and the official headnote reads:
(1) Although the Upper Tribunal is not bound by formal rules of evidence, it cannot act in such a way as to violate Parliamentary privilege, whether that be to interfere with free speech in Parliament or by reference to the separation of powers doctrine. The Tribunal cannot interfere with or criticise proceedings of the legislature.
(2) Courts and tribunals determine cases by reference to the evidence before them and not by reference to the views of others, expressed in a non-judicial setting, on evidence which is not the same as that before the court or tribunal. Indeed, even if the evidence were the same, the court or tribunal must reach its own views, applying the relevant burden and standard of proof.
The issue of Parliamentary privilege was also canvassed recently by the Court of Appeal, in R (Project for the Registration of Children as British Citizens & Anor) v Secretary of State for the Home Department (Rev 1)  EWCA Civ 19.