Giving evidence before the Scottish Parliament's Scotland Bill Committee this week, Lord Advocate Elish Angiolini was widely quoted as seeing some threat to the separate identity of Scots law through the current jurisdiction of the Supreme Court in devolution issues raised in criminal proceedings.

What the Lord Advocate said was this: “My slight concern is that, because of the approach of the Supreme Court, there is a real danger that we will not just have harmonisation of our criminal law, procedure and evidence, through that process, but that there will be a complete loss of identity for Scots law unless it is something which is genuinely rarely exercised in the context of something which is of substantial constitutional significance across the United Kingdom or where it is a very new piece of jurisprudence which is clearly ambiguous.”

She was speaking in the context of the recommendations of the expert group under Sir David Edward, set up to consider the impact of the referring of "devolution issues" to the Supreme Court in relation to her functions as head of the prosecution service.

In its report the expert group points out that the existing provision (s 57(2) of the Scotland Act 1998) deeming acts of the prosecution service under the Lord Advocate as devolution issues is "constitutionally inept", because these functions always did belong to the Lord Advocate and have not been devolved.

It recognises the delays that can be caused by current procedures, but the group believes that it is important to retain the jurisdiction of the Supreme Court, both for reasons of constitutional propriety and, more importantly, to ensure the consistent application across the UK of fundamental rights enshrined in international obligations. "That jurisdiction should, however, be clearly limited to ensuring compliance with the international obligations of the United Kingdom."

The group's proposal is that acts of the Lord Advocate as head of the prosecution system in Scotland should be taken out of s 57(2) and be replaced by a self-standing provision defining the jurisdiction of the Supreme Court in relation to criminal proceedings in Scotland. Recourse to the Supreme Court should in general be available only with leave of the High Court or special leave of the Supreme Court after determination in the normal course of appeal proceedings in Scotland.

The Lord Advocate said that 10,000 devolution issues have been raised, of which only a few have made it as far as the Supreme Court. That does not suggest that the jurisdiction of that body in relation to devolution issues is itself a problem; rather it is the side effects such as intimations to the Advocate General that take up unnecessary time and effort. However the Lord Advocate in her evidence to the committee spoke of seeking a threshold such as "constitutional significance" before a case can be taken to the Supreme Court.

In fairness her fears appear to relate as much to potential future extensions of international obligations, as the European Union adopts more common measures of the rights of individuals subject to criminal proceedings. At the same time, it is not immediately obvious why it is the role of the Supreme Court, as opposed to the manner in which questions relating to these new obligations are raised, that is the issue.

As is evident from the passages referred to, the committee itself accepts that appeal to the Supreme Court should not be taken lightly; nor is either the Supreme Court nor the High Court in Scotland likely to allow it to be otherwise. The Supreme Court itself has also drawn back from considering issues that it does not believe to be properly within its field of review. To date, so far as I am aware, it has not made any pronouncements on substantive Scots criminal law as opposed to matters of police investigation and fairness of court proceedings – which have usually given rise to important statements of principle by the court.

It may be that as discussed before the committee, the Lord Advocate will set out in writing for the committee's benefit the sort of tests she proposes might be applied by the courts. Until we have some such clarification, I remain to be convinced either that there is a real problem to be addressed or that additional criteria before a case can reach the Supreme Court are in fact necessary.