When British voters went to the polls back in June, they were asked to decide whether or not the country should leave the EU. They said yes. What they perhaps didn’t realize was that this decision would have even deeper implications, calling into question the very nature of the UK.

The Brexit results revealed a divided nation. Image: New York Times

There are three possible outcomes for the UK’s political set-up when British Prime Minister Theresa May triggers Article 50. In the first scenario, the UK remains in the same unitary state, minus its membership in the EU. Under the second scenario, parts of the UK, such as Scotland, secede. The third involves a change to the terms of devolution, a process put in place in the 1990s to decentralize decision-making powers.

The three scenarios differ in their likelihood, but they all have one thing in common: they would fundamentally change the nature of the UK. Such a daunting and historical decision cannot be made without the full and formal involvement of the city of London, Wales, Northern Ireland and Scotland.

Listen to what the people say

The first reason they should be at the negotiating table relates to proper representation. Theresa May’s Brexit argument is that Britain should “no longer be part of a political union with supranational institutions that can override national parliaments and courts”. In the same way, the UK’s subnational governments do not want such an important decision taken by institutions outside of their control.

Nicola Sturgeon, Scotland’s first minister, repeatedly says they cannot trust Westminster to represent them. Their Brussels is called Downing Street. This is even more discernible in the case of Northern Ireland. When the British and Irish governments endorsed the Good Friday Agreement, they accepted that the constitutional status of Northern Ireland would not be changed without the consent of the people of Northern Ireland.

A Pro-Europe demonstrator protests against the Brexit vote Image: REUTERS/Luke MacGregor

London: an economic powerhouse

The second argument relates to economic power.

The city of London accounts for 22% of the UK’s GDP, and as a major global trading hub and financial centre, it accounts for the lion’s share of the UK’s tax revenue – 28.6%. The second largest city, Manchester, accounts for only 3.3%. London also receives the overwhelming majority of immigrants who settle in the UK. According to recent census data, 37% of the capital’s workplace population was born abroad.

This, along with the fact that London is home to 40% of European headquarters for the world’s 250 top companies, led Deloitte to describe the city as the “business capital of Europe”.

Negotiating terms related to business and immigration without properly listening to London would be like trying to publish a fancy-covered book with a couple of torn chapters. As we saw in the UN Habitat III conference and in the UN Framework Convention on Climate Change, cities are dynamic deal- breakers and deserve a place in any international negotiation that affects them directly.

Avoiding a break-up

The third argument is tactical in nature. Downing Street faces the delicate task of trying to keep the UK together, whereas Scotland is again entertaining the idea of a second independence referendum, and Northern Ireland is concerned that the infamous 310-mile border that used to separate it from the Irish Republic will return.

If Westminster pushes subnational governments off the negotiation table, it is offering free ammunition to secessionist movements. National sentiments would be stoked. Multinational sovereign states, political science tells us, become vulnerable to break-up if the terms of the internal balance are adjusted unilaterally by the central government. Steamrollering is a more obvious risk than cultural distinctiveness.

All hands on deck

The fourth argument is simple: it would add brainpower to negotiations with the EU.

In July the former head of the UK government’s EU unit, Oliver Letwin, admitted that most British trade negotiators were actually working for the EU. As a result, the press has reported that the British government is rushing to hire trade experts from law and management consulting firms.

But the national government could seek other options. The foreign affairs departments and agencies of the UK’s subnational powers have assembled strong foreign policy and trade teams that could add talented manpower to the negotiations.

London & Partners, the international arm of the city of London, has a team of 160 and, as the acting chief executive Andrew Cooke told me, it could, for instance, “provide intelligence to the Brexit department on the business sentiment of overseas companies based in London.”

The Minister for UK Negotiations on Scotland’s Place in Europe and the Scottish Directorate for External Affairs have over 100 people at their disposal. Scotland, Northern Ireland and Wales even have official representations in Brussels, which could eventually add institutional strength to the British voice.

How it could work in practice

The city of London, Wales, Northern Ireland and Scotland cannot simply be added to the long and empathetic list of public, private and union players that are currently being consulted by the new Department for Exiting the European Union, led by David Davis. The establishment of a “direct line” to Davis, or the creation of a parallel “forum” for the devolved administrations, as more recently proposed by Theresa May, are more akin to political engineering than effective problem-solving.

Instead, the department should invite the administrations to nominate representatives to join negotiations with Europe. A Scottish government spokesman indicated to me over email that they “would be happy to give serious consideration” to that possibility. A spokesman from the Northern Irish government shared a long list of “areas of concern” (borders, energy, business, EU funds) that could only be plausibly addressed through full participation in the negotiations.

How would that work in practice? A good example comes from Canada. In the landmark EU-Canada Comprehensive Economic and Trade Agreement (CETA), all Canadian provinces were formal negotiating partners. This seemed to be pushed by the Europeans and accepted by the Canadians in order to inhibit enforcement complications. Wisely, back in 2010, Karel De Gucht, then EU commissioner for trade, said that “it was essential” to “put Canadian provinces on the negotiating table” because this is where “the real potential for a deepened economic relationship lies.”

Canada’s gesture of goodwill paid off politically. Often at odds with each other, Québécois and Canadian leaders have frequently been seen side-by-side promoting the trade agenda with the EU. A recent joint press release atypically underlined their commitment to “working together”. Quebec’s independence voices lost ground.

Making the terms work for all

In addition to the invitation to join negotiations, the UK government should also allow subnational governments to negotiate different relationships with the European Union. What is good for Wales may not be good for Northern Ireland, nor for the UK.

Under the exit agreement signed by the UK, specific chapters on the subnational governments should properly determine the terms of these new bilateral relationships with the European Union. One should not forget that Scots, Londoners and the Northern Irish voted to remain in Europe.

In practice, the UK should carry out some constitutional changes to allow Wales, Northern Ireland and Scotland to gain more autonomy in the international arena, including the power to adopt international treaties. This means a looser UK, with its constitutive parts enjoying international legal personality.

An interesting model comes from Belgium’s regions, which, since the early 1990s, apply the principle of in foro interno, in foro externo – they have international power (often replacing Belgium) in those areas for which they are also domestically responsible. This means they enjoy substantial powers in foreign policy and European matters. Even if they cannot bypass Belgium in EU-related issues, “their constitutional position gives them a serious amount of bargaining power within the Belgian federation”, as Maarten Vidal, spokesperson of the Flanders Department of Foreign Affairs, told me.

An example of this? Wallonia’s parliament has just rejected the signing of CETA, fearing the negative consequences to the region. Belgium’s Constitution requires the backing of all regional, federal and linguistic entities for the deal to be accepted by Belgium as a whole.

Uncharted territory

The fact that Britain is the first member state to exit the EU provides negotiations with a lot of latitude. Navigating uncharted territory may bend procedures. And in the past, the UK has recognized the importance of having subnational players handling their affairs globally.

As I wrote in Paradiplomacy: Cities and States as Global Players, the state of Sao Paulo – a top 20 world economy – has successfully established direct and formal relations with Britain (and also with Canada, France and the United States) through an agreement signed by Hugo Swire in 2013, then a minister of state at the Foreign Office.