Nathalie Lieven QC Published: 15th October 2012 This paper provides an overview of recent challenges to the Upper Tribunal (“the Tribunal”) decisions and the weight to be given to the decisions of specialist tribunals. It focuses on the issue of what approach the Court of Appeal will take to decisions of the Upper Tribunal , and in particular the “deference” , “margin of appreciation” or “appropriate weight” that will be accorded to decisions of the Upper Tribunal. The question of what deference should be given to decisions of the Tribunal can be a vexed one. It is a specialist tribunal , but does not always act as the specialist determiner of fact , this role instead being filled in many instances by the First Tier Tribunal (“the FTT”). The relationship between the role of the UT and the FTT (in its many guises) can itself cause considerable problems around which is the more specialist/expert and how the CA should approach their respective roles. Challenges to the Decisions of the Upper Tribunal