The economic and geopolitical consequences of a UK departure from the European Union are grave. This is why every government leader from the Western world supported continued EU membership for the UK. It is also why some rival powers welcome the intended exit and the prospect of an ensuing break-up of the United Kingdom, a scenario that would be a national catastrophe of historic proportions. The UK’s departure from the EU, given its far-reaching and long-term consequences, should not be implemented extemporaneously without detailed prior consideration of what model should be followed for the UK’s future relationship with the rest of Europe.

The referendum does not legally commit the UK to leaving the European Union. It is for the UK government alone to decide if, and when, to invoke Article 50 of the Treaty on European Union, by notifying the European Council (the governments of the 27 other EU Member States) of the UK’s intention to leave. Calls from some national and European politicians that this should occur immediately, or within any particular timeframe, carry no real weight and should be resisted.

We take it as a given that the survival of the United Kingdom must take precedence over the political imperative to act on the results of the referendum. There are very significant differences in voting patterns between the constituent countries of the United Kingdom—Scotland and Northern Ireland in particular—as well as between London and the rest of England and Wales. Leaving the EU poses the risk that any or all of these pro-EU regions will seek to leave the Kingdom given a choice between the EU and the UK. To commit national political suicide by triggering the disintegration of the United Kingdom, thereby provoking further and more serious national and international economic insecurity, would be an act of political folly which must be curtailed using all legal and political means available.

The Houses of Parliament, as well as the Scottish Parliament, Welsh Assembly, Northern Ireland Assembly, and London Assembly, must urgently debate whether and when, and under precisely what conditions, the UK government should activate Article 50. If there is such an activation, they must agree on what key objectives the UK should pursue in its future relations with the rest of the European Union. Given the extraordinary national importance of this decision, the UK government should not consider that it has a mandate to activate Article 50 unless it secures a qualified majority of Westminster MPs, as well as majorities of Members of the Scottish Parliament, the Welsh Assembly, the Northern Ireland Assembly, and the London Assembly. All UK elected officials are urged to take note of this proposal. Nothing less than the survival of the United Kingdom is at stake.