“There is no statutory definition of “claim” for the purpose of s 80 that would provide a basis for distinguishing an amendment to an existing claim from a new claim. …”
“… the First-tier Tribunal has only that jurisdiction which has been conferred on it by statute, and can go no further, …It is impossible to read the legislation in a way which extends its jurisdiction to include—whatever one chooses to call it—a power to override a statute or supervise HMRC’s conduct.”