Whose responsibility is the question of identification now?

THE opposition to the introduction of identity (ID) cards by the UK Parliament that has been voiced recently by the Scottish Government and some of the Scottish opposition parties is just one illustration of the increasingly complex debate taking place in Scotland as to the appropriate division of power between Westminster and Holyrood. Determining just where that dividing line should lie is the challenge facing the Devolution Review Commission, under Sir Kenneth Calman.

The commission will no doubt focus on the political ramifications of changes to the devolution settlement but it is to be hoped there may also be an opportunity to consider whether law-making powers in London and Edinburgh are allocated in a way that makes sense from a "legal" perspective and provides clarity to those who advise in this area.

With ID cards there are a number of legal questions that arise for a Scottish Government that may wish to oppose the introduction of such a scheme. The first is whether the Scottish Parliament is empowered to legislate in relation to ID cards. Although having such a power could not prevent Westminster from passing a UK-wide scheme, it could enable the Scottish Parliament to modify or even revoke that scheme at some future date.

The answer depends at least in part on whether it can be said the making of law on ID cards is "reserved" to Westminster. Needless to say, the Scotland Act 1998 is silent on the specific issue of an ID card scheme, so a more detailed analysis of that Act is necessary. Would an Act of Parliament about ID cards be an Act relating to the defence of the realm, data protection or the questions of nationality, immigration and the "issue of travel documents"? If so, it is pretty clear Westminster enjoys the exclusive right to legislate. If, however, an ID card scheme is not about immigration control and is instead characterised as being about access to public services – something successive Scottish administrations have rejected – then that would appear to be an area in which Holyrood could have a role.

To the general question of how to work out if a new policy initiative is one on which Holyrood has power to legislate, can be added further queries about the legal coherence of the devolution settlement. Opposition to ID cards is based in part on concerns about privacy and data protection. Data protection is itself a reserved matter, with the UK information commissioner having powers to deal with data protection breaches throughout the UK. That same commissioner is also responsible for implementing the UK Freedom of Information (FOI) Act and polices the release of information by UK government departments, even when they operate in Scotland. However, the Scottish Parliament is entitled to legislate on FOI in Scotland and we have a Scottish information commissioner who is responsible for FOI and Scottish public authorities, but without responsibility for data protection. Is there any clear principle – from a political or legal perspective – that underpins this division of responsibility?

From the Scottish Government's perspective, there is a straightforward answer to these questions: an independent Scotland that has power to legislate independently on all of these issues. For a commission focused on understanding and perhaps revising the current boundary, the task is likely to be more difficult.

• Christine O'Neill is head of the public sector services group at Brodies.