only if it thinks that the Tribunal may have made an error of law, and

only once in relation to an appeal.

in the case of an application by the appellant made while he is in the United Kingdom, within the period of 5 days beginning with the date on which he is treated, in accordance with rules under section 106, as receiving notice of the Tribunal’s decision,

in the case of an application by the appellant made while he is outside the United Kingdom, within the period of 28 days beginning with the date on which he is treated, in accordance with rules under section 106, as receiving notice of the Tribunal’s decision, and

in the case of an application brought by a party to the appeal other than the appellant, within the period of 5 days beginning with the date on which he is treated, in accordance with rules under section 106, as receiving notice of the Tribunal’s decision.

rules of court may specify days to be disregarded in applying subsection (3)(a), (b) or (c), and

the appropriate court may permit an application under subsection (1) to be made outside the period specified in subsection (3) where it thinks that the application could not reasonably practicably have been made within that period.

written submissions of the applicant, and

where rules of court permit, other written submissions.

a procedural, ancillary or preliminary decision, or

a decision following remittal under section 103B, 103C or 103E.

in relation to an appeal decided in England or Wales, the High Court,

in relation to an appeal decided in Scotland, the Court of Session, and

in relation to an appeal decided in Northern Ireland, the High Court in Northern Ireland.