THE RIGHT TO LEAVE

On September 14, in Cardiff, an unexpected alliance came together around the question every centralising structure ultimately fears. By joining forces, the leaders of the Scottish National Party, Plaid Cymru and Sinn Féin — John Swinney, Rhun ap Iorwerth, Michelle O’Neill and Mary Lou McDonald — did more than sign a memorandum of circumstance. They challenged the very architecture of the state by demanding that the British government prepare for, plan and facilitate constitutional change rather than keep its doors locked. If membership of a political union is genuinely voluntary, who ultimately holds the sovereign power to bring that membership to an end? Behind the electoral strategies of the independence movements lies a more fundamental challenge to the institutional monopoly over our right to determine our own political future.

The illusion of a homogeneous bloc

The United Kingdom bears the nature of its political construction in its very name: it is a union, not an administrative monolith fixed for eternity. Scotland, Wales and Northern Ireland are not simply electoral districts, but nations shaped by histories, identities and political trajectories that resist dissolution. Devolution at the end of the last century certainly transferred powers to their respective institutions, but devolving competences has never meant returning sovereignty.

Today, the imbalance of that architecture is exposed through three different constitutional paths. While the Good Friday Agreement embeds in law the possibility of Irish reunification on the basis of popular consent, Scotland remains dependent on Westminster for the legal opening of another independence referendum: in 2022, the UK Supreme Court held that the Scottish Parliament could not legislate unilaterally for such a vote because the proposed referendum related to matters reserved to the United Kingdom Parliament. The centre therefore retains the key to the procedure through which the centre itself may be challenged. Cour suprême du Royaume-Uni

The monopoly over exit

Every political architecture argues for its own stability, invoking economic chaos, fiscal complexity or fragmentation to justify the preservation of existing arrangements. But the paradox becomes impossible to ignore when a political community seeks to test the nature of its own membership: how can a people meaningfully consent to a union if the procedure through which that consent may be withdrawn remains controlled, in the final instance, by the very authority from which it seeks greater independence?

This is where institutional consent becomes deeply ambiguous. A system in which the conditions of departure ultimately depend upon the authority from which one wishes to depart risks transforming a voluntary union into a relationship of guardianship.

The logic of centralisation

An oversized political structure will always find rational arguments for its own size. Unity simplifies, the centre protects, concentration rationalises and provides strength against external threats: such is the familiar language through which centralisation justifies itself. The accumulation of power is presented not as a political choice, but as necessity, seriousness and solidarity.

Conversely, every attempt to return power to the periphery is quickly described as disorderly, irrational or populist. Yet what appears from Westminster as dangerous fragmentation may look very different from Edinburgh, Cardiff or Belfast: the recovery of a meaningful capacity to act.

Changing masters is not freedom

We should resist, however, the comforting illusion that separatism alone solves the problem. Replacing a British centre with a Scottish or Welsh one would hardly constitute a political revolution if power remained concentrated in the hands of a new governing elite. Leaving one centralising capital only to reproduce another at a smaller scale is an empty victory if the vertical structure of authority remains intact.

The deeper demand is not simply separation, but the return of power towards the base. The question is not only whether independence should occur, but in which direction power should then travel: towards new national or supranational institutions, or towards the individuals and communities who live directly with the consequences of political decisions? Decentralisation is never measured by the number of flags that are raised, but by the actual distance between a decision and the lives of those affected by it.

The test of continuous consent

Absolute localism is no more convincing than the religion of centralism. Small political units can generate their own forms of tyranny, just as a larger state can sometimes protect fundamental rights that a local community would prefer to violate. The challenge of our time is therefore not to multiply decision-making centres blindly, but to abandon our docility towards them and insist that every power which can genuinely be exercised closer to the base should have a presumption in favour of being returned there.

A political union worthy of the name cannot depend solely on inherited consent. It must remain capable of securing the continuing adherence of the peoples who compose it. The Cardiff gathering therefore reaches beyond Britain’s immediate constitutional dispute: it reminds us that the consent of previous generations cannot indefinitely settle the political status of those now living. If a structure can sustain itself only by retaining control over the conditions under which its members may challenge or leave it, then the voluntary nature of that union inevitably becomes open to question. Andy Burnham’s government now faces that test in concrete form — but for how long?