Tomorrow is likely to go down in history. Prime Minister Theresa May will trigger Article 50 and officially begin the Brexit process.
Here’s everything you need to know.
What is Article 50?
Article 50 refers to the 264-word clause of the Treaty on European Union (often referred to by the marginally more memorable moniker, the Lisbon Treaty) allowing countries to leave the European Union (EU).
Any country can leave the union subject to “its own constitutional requirements”.
What will happen tomorrow?
The cabinet is expected to meet tomorrow morning rather than their usual Tuesday meeting to allow for May’s top ministers to discuss the Article 50 notification.
Then it is expected the Prime Minister will face her standard Wednesday grilling in the House of Commons from midday, with May expected to make a statement following Prime Minister’s Questions.
Meanwhile, the notification will take place around the same time.
So how will we notify?
There is no stipulation in the article for the form of the notification, but presumably a cheeky text message would not meet the standard for statecraft required.
Instead, the UK’s ambassador to the EU, Sir Tim Barrow, will hand-deliver the notification letter to the European Council and its president, Donald Tusk. The letter will be signed by the Prime Minister.
What will be in the letter?
We don’t know yet, but we will have our first chance to see the historic document later in the afternoon.
How long will negotiations last?
From the notification date the UK will have two years to negotiate the terms of exit.
The negotiations will follow the path set down by another article in a connected Treaty. The next bit of obscure constitutional jargon we will all need is Article 218(3) of the Treaty on the Functioning of the European Union.
This one is less important though: it just says the European Council must authorise the opening of negotiations and appoint a negotiator.
When will the UK officially leave the EU?
If this process is followed correctly the UK will have left the EU officially by the start of April 2019.
Whether this happens in practice might be rather more complicated. The vast body of EU law and regulations (not to mention the institutions which do the regulating) will probably take a significant amount of time to duplicate or remove.
Transitional deals around the UK’s leaving process have been called for in some quarters of the business community, although so far we have no detail on what the government’s priorities will be.