By Alison L Young  
Sir David Williams Professor of Public Law, University of Cambridge 

Previous posts on devolution have explained that devolution is not the same as federalism. Whilst there are legal limits on the powers of the devolved legislatures, this is not the case for the UK Parliament. The UK Parliament can legislate for the UK as a whole, for England, and also for Wales, Scotland, and Northern Ireland, even when this is within an area that has been devolved. How does this work? What mechanisms are used to ensure that relations run smoothly between the UK and the devolved legislatures and governments? 

This post will explain that, whilst there are some legal mechanisms, most of the relationship between the different governments and legislatures are determined by non-legally enforceable rules – such as constitutional conventions, and agreements between the different governments and legislatures, referred to as concordats and the memorandum of understanding.  

The role of the courts 

If a devolved legislature has acted beyond the sphere of its competences, then it is possible for an individual to go to court to enforce this limit. For example, Scotland, Wales, and Northern Ireland do not have the power to enact legislation that breaches ‘Convention rights’ (that is, certain rights set out in the European Convention on Human Rights). If an individual believes that Scottish legislation breaches Convention rights, she will be able to go to court and seek a legal remedy. The Scottish legislation could be quashed if it breached these rights.  

Mechanisms also exist to help determine whether legislation is within the competence of the devolved legislatures before it is enacted. The UK law officers, or the law officers of the devolved Governments, can initiate an action before the UK Supreme Court to determine whether legislation is within the competences of the devolved legislature.

This can take place after the legislation has been passed by the devolved legislature, but before it receives royal assent from the Monarch – referred to as the reference procedure. The Supreme Court’s assessment of Scotland’s incorporation of the UN Convention of the Rights of the Child, for example, used this special reference procedure. The UK law officers asked the Supreme Court to assess whether the incorporation was beyond the scope of the powers of the Scottish Parliament.  

The UK law officers tend to bring references when they think that devolved legislatures have exceeded their powers. It is also possible for the law officers of the devolved governments to bring a reference to check whether legislation is within the scope of their powers before it is given royal assent. This helps to provide legal certainty, hopefully preventing legal challenges once the devolved legislation has been enacted.  

The Sewel Convention 

The Sewel convention regulates issues that arise when the UK Parliament legislates on a devolved matter for Scotland, Wales, or Northern Ireland. The Sewel convention is also expressed in legislation. Section 2 of the Scotland Act 2016 inserted a new section into the Scotland Act 1998, section 28(8). This section states that ‘it is recognised that the Parliament of the United Kingdom will not normally legislate with regard to devolved matters without the consent of the Scottish Parliament’. A similar provision was inserted into section 107(6) of the Government of Wales Act 2006 by section 2 of the Wales Act 2017.  

Despite this legal recognition of the Sewel convention, the Supreme Court in the first Miller  decision made it clear that the Sewel convention was not legally enforceable. It is not possible to go to court and challenge UK legislation on a devolved matter which was enacted without the consent of the relevant devolved legislature. The court gave two reasons.

First, the wording of section 2 of the Scotland Act 2016 (the Wales Act 2017 was not in force at the time of the first Miller decision) does not support the legal enforcement of the convention. It merely states that ‘it is recognised that the UK Parliament will not normally legislate’ on a devolved matter without consent.

The Supreme Court concluded that this meant that, whilst Parliament was recognising the need for consent, its intention was to recognise the Sewel convention as a convention. Parliament did not intend to make it a legally enforceable statutory provision. If Parliament had intended to make the Sewel convention a legally enforceable statutory provision, it would have worded this provision differently. For example, it could have said ‘The UK Parliament will not legislate for Scotland without its consent’. However, it did not do so.  

Second, the legislation states that ‘the UK Parliament will not normally legislate’ without consent. This suggests that situations can arise when it would not be normal to ask a devolved legislature for its consent, or where it would be acceptable for the UK Parliament to legislate in a devolved area even when a devolved legislature refused to give its consent. What does ‘normally’ mean? The Supreme Court concluded that this would depend on political circumstances. Consequently, it was not something that was suited for the courts to enforce.  

The UK Government, when initiating legislation, will set out in an explanatory memorandum to a Bill whether it thinks that the Sewel convention applies. The UK Government is then responsible for obtaining this consent. Consent is given through the enactment of a legislative consent motion in the Scottish Parliament, the Senedd Cymru (Welsh Parliament), or the Northern Ireland Assembly.  

The problem with Conventions 

Two main problems can arise with regard to constitutional conventions. First, it can be difficult to determine what they mean. The content of the Sewel convention may appear to be easier to define as it is recognised in legislation. It was also written into the Memorandum of Understanding between the UK, Welsh, Scottish, and Northern Irish Governments. This is an inter-governmental agreement that is also not legally enforceable.  

Nevertheless, differences of opinion still arise as to the content of the Sewel convention. The different governments may disagree as to the meaning of ‘normally’ – this was particularly pertinent with regard to the enactment of Acts of Parliament regulating the UK’s exit from the European Union that were enacted without the consent of some or all of the devolved legislatures.

Also, there are arguments that the Sewel convention is wider than its recognised form in legislation. In particular, there is evidence to suggest that it also extends to situations when the UK Parliament legislates in a manner that would alter the devolution settlement between the UK and Scotland, Wales, or Northern Ireland. 

Second, problems arise as to the enforcement of conventions. If the UK were to breach the Sewel convention what, if anything, could the devolved legislatures do? Normally, we argue that constitutional conventions are followed because of the political consequences of failing to follow the convention. The UK could be criticised for failing to adhere to the Sewel convention. However, as the UK Parliament can legally legislate on a devolved matter, and there is no legal requirement for consent, why should the UK be concerned if it breaches the Sewel convention? Will political criticism suffice to ensure the UK adheres to the Sewel convention? 

The Sewel convention requires members of the UK Parliament to want to act in a manner that upholds good relations between the UK Parliament and the devolved legislatures. It is perhaps understandable, therefore, that the devolved legislatures have been critical of the Sewel convention, particularly surrounding Brexit.  

Inter-governmental relations 

Agreements also exist to regulate the relationship between the UK and the devolved governments. These are also found in the memorandum of understanding. These have recently been subject to review. The review states that the new relationship between the UK and the devolved governments is ‘built on principles of mutual respect and trust, respecting the reserved powers of the UK Government and Parliament and the devolved competences of the Scottish Government, Welsh Government, Northern Irish Executive, and their legislatures’. The new mechanisms for regulating inter-governmental relations aim to provide a new system of meetings between members of the various governments and civil servants, providing greater transparency and accountability.  

This is important to ensure that the governments can work together effectively. This is even more important when faced with a national emergency, such as the Covid pandemic, which required an effective and co-ordinated response that was also suited to varying local conditions. It is also important to ensure that the UK and devolved legislatures can effectively hold their respective governments to account. This requires openness about agreements reached in inter-governmental meetings. The mechanisms also provide for a better way of resolving disagreements between the different governments.

The mechanisms regulating devolution provide an insight into the nature of the UK constitution, particularly as regards the impact of parliamentary sovereignty and the complex amalgamation of legal and political checks and balances. It remains to be seen whether this unique set of constitutional arrangements will be able to facilitate good relationships between the UK and the devolved legislatures and governments which have been put under strain by Brexit and the Covid pandemic.