EU referendum result: What is Article 50? How long will it take for Britain to leave the EU?

Britain is not out of the EU yet. We will leave, but how soon and under what conditions, no one knows.

The founding fathers of the EU did not envisage that any member state would ever leave – and so far, with the minor exception of Greenland, none has.

However, in the Treaty of Lisbon, which Gordon Brown signed on behalf of the UK in 2007, there is an Article 50 which sets out the rules should a country decide to quit the club.

The actual process of getting out will begin when the British government formally notifies Brussels that it is invoking Article 50. An argument is already starting over how soon that should be done, with the Labour leader Jeremy Corbyn saying it should happen immediately, and others urging caution and delay.

One cause of delay will be a Conservative leadership election. Negotiations cannot realistically begin until we know who is doing the negotiating on the British side.

Nigel Farage has suggested that a negotiated exit is not as complicated as all that. However, under Article 50, the British government will now have to negotiate with the other 27 EU states to see whether they can agree a trade deal that protects British interests. Different states will have different interests. Germany will be concerned about minimising the damage to the whole EU project, France will want to look after its farmers, Poland will be concerned about the three quarters of a million Poles living in the UK, and so on.

The negotiators on the EU side may choose to play hard ball, to discourage others from following the UK’s example. Fabian Zuleeg, an analyst at the European Policy Centre told the Observer that it is not in their political interest “to concede a lot to the UK,"

The time scale most often quoted is two years, though some say it may take a lot longer. And while it drags on, the UK continues to be a UK member, subject to EU law.

This summary of what Article 50 is and how it works from a European Parliament briefing paper:

The right of a Member State to withdraw from the European Union was introduced for the first time with the Lisbon Treaty; the possibility of withdrawal was highly controversial before that. Article 50 TEU does not set down any substantive conditions for a Member State to be able to exercise its right to withdraw, rather it includes only procedural requirements. It provides for the negotiation of a withdrawal agreement between the EU and the withdrawing state, defining in particular the latter's future relationship with the Union. If no agreement is concluded within two years, that state's membership ends automatically, unless the European Council and the Member State concerned decide jointly to extend this period.

The legal consequence of a withdrawal from the EU is the end of the application of the EU Treaties (and the Protocols thereto) in the state concerned from that point on. EU law ceases to apply in the withdrawing state, although any national acts adopted in implementation or transposition of EU law would remain valid until the national authorities decide to amend or repeal them. A withdrawal agreement would need to address the phasing-out of EU financial programmes and other EU norms.

Experts agree that in order to replace EU law, specifically in any field of exclusive EU competence, the withdrawing state would need to enact substantial new legislation and that, in any case, complete isolation of the withdrawing state from the effects of the EU acquis would be impossible if there is to be a future relationship between former Member State and the EU. Furthermore, a withdrawal agreement could contain provisions on the transitional application of EU rules, in particular with regard to rights deriving from EU citizenship and to other rights deriving from EU law, which would otherwise extinguish with the withdrawal.

The document can be seen in full here.