https://www.slab.org.uk/guidance/power-of-the-high-court-to-determine-interests-of-justice-test-in-appeal-applications/
The High Court may take a contrary view in any case where we have refused an application for criminal legal aid for an appeal because we were not satisfied it was in the interests of justice. If so, we must then grant legal aid for the appeal. This power of the High Court to make its own determination as to the interests of justice is conferred by section 25(2A) of the Legal Aid (Scotland) Act 1986. The court may consider the matter if it is invited to do so by the appellant, or of its own volition. The determination must, however, be made before the appeal is disposed of.
Although the court has the power to determine that it is in the interests of justice for the appellant to receive legal aid for the appeal, it does not have the power to grant legal aid. That remains a matter for us, and we must make legal aid available immediately we are notified of the court’s determination.