https://www.slab.org.uk/guidance/availability-of-legal-aid-and-tests-you-should-address-in-an-application-for-legal-aid-for-an-appeal-to-the-uk-supreme-court/
Legal aid is available in connection with any reference, appeal or application for special permission to appeal to the UK Supreme Court. Any court consisting of two or more judges of the High Court of Justiciary may in certain circumstances refer a compatibility issue to the UK Supreme Court [section 288ZB of the Criminal Procedure (Scotland) Act 1995]. Section 288AA provides that an appeal against a determination of a compatibility issue by a similarly constituted court shall lie to the UK Supreme Court with leave of the court concerned or with special leave from the UK Supreme Court.
Where the Appeal Court has granted leave to appeal to the UK Supreme Court:
When submitting an application please provide:
There should be no need for Regulation 15 (of the Criminal Legal Aid (Scotland) Regulations 1996) legal aid as the appeal application can be considered by us very quickly.
Where the Appeal Court refuses to grant permission to appeal to the UK Supreme Court, an application for special permission to appeal to the UK Supreme Court must be submitted. No Regulation 15 (of the Criminal Legal Aid (Scotland) Regulations 1996) cover is needed, but before the application for special leave can be lodged, we will consider granting an increase under advice and assistance to fund an Opinion from counsel on the prospects of success for this.
If the Opinion is supportive, then alongside your application you should submit:
We require to be satisfied that it is in the interests of justice to make legal aid available for the application for special permission to appeal to the UK Supreme Court. The undue hardship test will also be applied, where there was no legal aid at first instance.
Where legal aid is granted, this covers all work required to lodge the application for permission to appeal to the Supreme Court.
If permission is granted, the grant can be updated for the full hearing before the UK Supreme Court.
If permission is refused, the grant of legal aid ceases at that conclusive stage.