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

As has been noted in previous posts, the Brexit referendum may have provided a UK-wide majority in favour of the UK exiting the EU, but this was not reflected in all the component parts of the UK. Whilst a majority voted in favour of Brexit in England and Wales, in Scotland and Northern Ireland the majority voted in favour of remaining in the EU.  

Brexit also has a different impact across the UK. This is particularly true in Northern Ireland – the component of the UK to have a land border with another EU country, Ireland. The Northern Ireland Protocol provides for specific regulation in Northern Ireland. EU rules regulating trade in goods and services continue to apply in Northern Ireland.

Also, whilst goods may travel freely across the border between Ireland and Northern Ireland, goods travelling from the UK to Northern Ireland which may later travel to Ireland are subject to checks in the same manner as goods leaving the UK for another EU Member State.  

Brexit, therefore, has clearly had an impact on devolution. Its effects have also gone beyond an increase in divergence across the UK. It has also added to tensions which, if not appeased, run the risk of fragmenting the United Kingdom. 

Problems arising from Brexit 

To understand the impact of Brexit on devolution, we need first to understand a little about how international law works. Different States may enter into agreements, or ‘treaties’, with each other or form international organisations that regulate specific issues. However, merely because the UK has entered into a Treaty does not mean that the provisions of this Treaty can be relied upon in UK courts.

First, a Treaty has to be ratified. In the UK, this means that the Treaty has to be laid before Parliament, providing the House of Commons and the House of Lords with the opportunity to vote against ratification of the Treaty. If ratification fails, then the provisions of the Treaty will not be binding on the UK, even through the mechanisms of international law. 

Second, the UK is referred to as being dualist as opposed to monist. This means that international law, even ratified Treaties, do not automatically become part of UK law. You cannot go to a UK court and rely on the provisions of an international Treaty. To become part of UK law, the Treaty needs to be implemented by legislation. You can then rely on the legislation, which will set out how individuals can use the Treaty in UK law.  

In spite of devolution, the power to negotiate and enter into Treaties remains with the United Kingdom, as does the power to ratify a Treaty. However, the UK may enter into Treaties that involve areas governed by the devolved legislatures. It is therefore for the devolved legislatures to implement these Treaties into their law. Devolved legislatures may also decide to implement Treaties which have not been implemented in the UK.

For example, Wales has implemented the United Nations Convention on the Rights of the Child and Scotland enacted a Bill to implement the same Treaty, although the Supreme Court concluded that the way in which Scotland would have implemented the Treaty was beyond the scope of the powers of the Scottish Parliament.  

Just to add to the complications, many of the areas regulated by the European Union were in areas that had been devolved – e.g. agriculture. The European Union also established a single market for goods and services across the EU. This meant that producers who were able to sell their goods in one EU country could sell the same goods across the EU. This also meant that the UK enjoyed a single market for goods and services in a similar manner. However, post-Brexit, this would no longer be the case, meaning that there would be the need to legislate if the UK wished to retain a single market within the UK in goods and services.  

This gave rise to two problems. First, what should happen to the law-making powers repatriated from the EU to the UK? Should those powers that fell in areas that had been devolved return to Scotland, Wales, and Northern Ireland and not to the United Kingdom? Second, should there be regulations to establish a new UK-wide single market (with the exception of Northern Ireland due to the Northern Ireland Protocol)? Should a producer who could sell their goods in Scotland, for example, also be able to sell the same goods in England and Wales in the same way? Also, who should be in charge of determining these common rules, and when it would be possible for these rules to diverge to take account of local situations?  

Top-down or Bottom-up?  

The Brexit referendum may have triggered the UK’s exit from the European Union, but it did not provide a detailed blueprint as to the UK’s future relationship with the European Union. Whilst the constitutional responsibility for these negotiations clearly rested with the United Kingdom, issues arose as to the extent to which UK Ministers should talk to, and take account of, the views of Ministers from Scotland, Wales, and Northern Ireland. It soon became apparent that the views of the United Kingdom were different from those of Scotland and Wales.  

Scotland wished to repatriate powers back to Scotland. Wales also desired repatriation of powers, but also had a willingness to share powers between the United Kingdom and Wales. Scotland and Wales both wanted to have a power to continue to mirror provisions of EU law, post Brexit, including developments of EU law taking place after the UK had left the EU.

Wales, in particular, was keen to preserve consumer protection laws, social rights and environmental rights. Both Scotland and Wales also preferred a form of ‘soft’ Brexit which would involve preserving the free movement of goods, services, people and capital with the European Union. Both also wanted a role in the negotiation process to protect their interests.  

These desires stood in stark contrast to those of the United Kingdom Government. First, the UK Government preferred a form of ‘hard’ as opposed to ‘soft’ Brexit. It did not desire the UK continuing to enjoy free movement with the rest of the European Union – or, more specifically, would prefer to maintain free movement of goods, services, and capital but not of people. There was also no desire to mirror EU law in the future.  

Second, the UK Government wished to perform the main negotiation role. The Government did establish a special Joint Ministerial Committee to look at Brexit negotiations – this is a committee composed of Ministers from Westminster, Scotland, Wales, and Northern Ireland. However, these committees only met sporadically, at the initiation of the United Kingdom Government. There was frequent criticism of the lack of transparency of these proceedings, and a feeling amongst the devolved Governments that their views were not taken into account, particularly as the decisions of the Joint Ministerial Committee did not bind the UK Government. 

This led the devolved Governments to believe that the UK Government based in Westminster favoured a ‘top down’ approach. They argued that this was apparent not only through the negotiations over Brexit, but has prevailed post-Brexit. Some refer to this as a form of ‘muscular Unionism’ – where the UK may devolve powers, but still seeks to legislate with regard to devolved matters in Scotland, Wales, and Northern Ireland, sometimes even without their consent.  

In a series of posts, we will be investigating these issues more specifically. First, we will look at the tension between the UK’s Withdrawal Act, and Scottish and Welsh legislation designed to implement EU law in Scotland and Wales. How were these tensions resolved, and what does this tell us about the nature of the Union? Second, we will look at the UK Internal Market Act 2020, which creates a single market across the UK. Why was this legislation so controversial and has this placed the Union under further strain? Third, we will look at intergovernmental relations post-Brexit. Are these still conducted in a ‘top-down’ manner and what might the consequences of this approach be in Scotland, Wales, and Northern Ireland?