Stephen Tierney: The Lord Advocate’s Reference: The Constitutional Significance of Referendums and Electoral Processes

The Lord Advocate’s Reference to the Supreme Court asks if the proposed Scottish Independence Referendum Bill relates to reserved matters under the Scotland Act 1998. Core to the Lord Advocate’s case is the claim that the referendum proposed by the draft bill would be ‘advisory’, ‘consultative’ or ‘non-binding’. If this is the case then it can be argued that the Draft Bill and the referendum it proposes to authorise would not ‘relate to’ the reserved matters of the Union and Parliament by virtue of having ‘no effect in all the circumstances’ – the test set by Scotland Act 1998 s.29(3).

In an earlier post I queried whether the referendum proposed by the Scottish Government could be said to have no ‘effect’ within the context of the United Kingdom constitution where constitutional conventions now seem to attach both to the holding of referendums and the implementation of their results. In this post I reflect upon another way in which the proposed referendum might be said to have constitutional ‘effect’: as an electoral process which bears inherent constitutional significance. In considering this question I make reference to case law from Spain which has also considered the nature and constitutional significance of referendums in electoral context. 

A referendum is not just a ‘form of democratic engagement’ – the term used by the Lord Advocate in discussing citizens assemblies and the like (Lord Advocate’s Written Submission, para 46). Referendums are nation-wide electoral events organised through the machinery of the electoral process, under the auspices of the Electoral Commission, and regulated both by the Political Parties, Elections and Referendums Act 2000 and any additional legislation tailoring the 2000 Act to the specific circumstances of a particular referendum. Much of this law is now devolved, and the Lord Advocate’s Reference refers to the legislation already put in place by the Scottish Parliament to regulate and operate the referendum which the proposed Bill purports to authorise. For example, the draft Scottish Independence Referendum Bill proposes the involvement of the Electoral Commission in the process by way of the Referendums (Scotland) Act 2020.

The Advocate General alludes to the fact that: 

‘legislation for a referendum on independence is required precisely because statutory authority is necessary to authorise the expenditure of significant financial resources on the exercise, and to direct the performance of the functions of counting officers and registration officers to conduct the referendum. The mechanics of this are addressed in the Referendums (Scotland) Act 2020, but clause 4 of the Draft Bill [which provides that the Referendums (Scotland) Act 2020 applies for the purposes of the proposed referendum] is required to apply those provisions.’ (Advocate General’s Written Submission, para 77) 

In other countries the law considers the distinction between a public consultation exercise and a referendum to be of the first importance. For example, the Spanish Constitutional Court (Tribunal Constitutional) has asserted in a judgment of October 2017 that a referendum is not merely a consultation because it involves the “direct participation of citizens in public affairs”.  It therefore engages the entire electorate and not just respondents to a poll. The people are brought together by the state as “the electoral body” and hence as “the constituent power” to make a collective decision. 

Three key points of distinction between a referendum and a public consultation emerge from this analysis. The first concerns those who participate. A public consultation can comprise any collective body or any collection of groups. According to the Spanish Constitutional Court, participants in public consultations express an opinion as individuals (uti singulis) or as a members of groups (uti socius). This can take any form, be that social, economic or cultural, as well as political. They do not take part in these events as citizens (uti civesper se. This contrasts with the mobilisation of the entire electorate speaking together, which occurs in a referendum.

The second point is that the electoral body comes together to make a decision not merely to express a view. The electoral body acts as a decisive body in elections when it determines who will enter parliament, but it does so equally in a referendum: in my earlier post I observed that simply because a referendum result is not self-executing does not mean it is not of binding constitutional effect. For the Spanish court the characterisation of a referendum as an electoral event, and not simply the expression of the various viewpoints of an amorphous collection of individuals and societal groups, is crucial because it mobilises the general will of the citizenry as one collective body: the people who underpin and hence legitimise the constitution itself (for discussion on this point I am grateful to a paper on file with the author: ‘Independence referendums and the Spanish Constitution’ by Lucía Payero López). The concepts of ‘general will’ and ‘constituent power’ are not typically used within the British constitutional lexicon, but the idea that a referendum is an electoral event in which the entire people come together to make a decision analogous to the decision they make in a general election is one that does resonate within the UK constitutional tradition. 

Finally, there is the sense in which electoral events, of whatever kind, have inherent constitutional significance. The distinction between referendums and popular consultations is marked by the specific process of the former which is “organised and externalised through an electoral procedure”. According to the Spanish Constitutional Court in an earlier case from September 2008, this means that referendums are “based on the census, managed by the electoral authority and ensured with specific jurisdictional guarantees”. A referendum is an expression of public power which “summons all the people of a given territorial area so that they can exercise ‘the fundamental right to participation in public affairs’ by way of an electoral process”, with the typical process guarantees that attend an electoral process.”

These cases are helpful and to some extent transferable in helping to understand the nature, specificity and significance of referendums within the United Kingdom constitution. The main points of salience for the Spanish court: the participation of the whole body of citizens within a jurisdiction, the role of the referendum as a decision-making mechanism, and the formality of the process, are all features of referendums in the United Kingdom. These are reflected in the infrequent use of referendums, the typically highly significant matters with which they have been concerned, and the fact that the result of each has been respected and implemented by Parliament. These features also bolster the argument that a constitutional convention now in fact requires the implementation of a referendum result. 

To conclude, I have suggested that it is difficult to consider the referendum on independent statehood which the Scottish Government proposes to be potentially ‘non-binding’ when a referendum is understood as a constitutional commitment of those organising the process that the outcome is decisive, meaningful and creative of a political and constitutional obligation to implement the result. This argument is given additional weight when we also observe that referendums are not merely consultation exercises but electoral events designed by their nature to arrive at significant constitutional decisions. If a referendum’s characterisation as an electoral process helps give rise to a constitutional expectation that it will be implemented, then it is equally difficult to say that it has no ‘effect in all the circumstances’ (SA s.29(3)), and accordingly that it does not relate to the reserved matters of the Union and of Parliament. 

Stephen Tierney is Professor of Constitutional Theory at the University of Edinburgh and author of Constitutional Referendums: The Theory and Practice of Republican Deliberation. He also serves as Legal Adviser to the House of Lords Select Committee on the Constitution. This post is written in a personal capacity.

(Suggested citation: S. Tierney, ‘The Lord Advocate’s Reference: The constitutional significance of referendums as electoral processes’, U.K. Const. L. Blog (5th October 2022) (available at