Part 1: Digital Markets Applications for review Section 103: Applications for review etc
The section allows decisions taken by the CMA in connection with its digital markets functions to be reviewed by the CAT. It applies to any decision taken by the CMA in connection with its digital markets functions, other than decisions made in connection with the CMA’s mergers functions (see section 66) and decisions to impose a penalty under section 85 or section 87 (see section 89). The CAT will decide these challenges on the same basis as the courts decide applications for judicial review. Case law suggests possible grounds of challenge include: (i) that an error of law was made; (ii) that there was a material procedural error; (iii) that a material error as to the facts has been made; and (iv) that there was some other material illegality (such as unreasonableness or lack of proportionality).
	Subsections (1) and (2) set out that, any party with a "sufficient interest" in a decision has the right to make an appeal. "Sufficient interest" is a test for who has standing to bring a challenge, which is already used by the CAT and also the Administrative Court. These provisions mean that undertakings who are subject to the decision as well as third parties, which may include competitors of the undertaking, who have a particular interest in the subject matter of the decision can challenge that decision.
	Subsection (3) provides that a designated undertaking will always be expected to comply with a decision until the outcome of an appeal is known, unless the CAT makes an interim order to the contrary.
	Subsections (6) to (8) provide that decisions of the CAT may be appealed to the appellate court for that jurisdiction. As the CAT is a UK-wide tribunal, at the beginning of a case, the CAT will decide which of the UK’s three legal jurisdictions it is sitting in for the purposes of that case. If the CAT decides it is sitting in Scotland, for example, subsection (6) means that any appeals of CAT decisions in that case should be made to the Court of Session.