Brexit vote: How can Article 50 be extended?
As you've probably noticed by now, time is running short for Theresa May to finalise a Brexit deal.
So how easy would it be to delay the process?
First of all, it would mean extending the Article 50 negotiating period.
When people talk about Article 50, they are referring to Article 50 of the EU's Lisbon Treaty - the section that sets out what happens when a country decides it wants to leave the European Union.
Most importantly, Article 50 allows a two-year period for negotiations on divorce - finalising a withdrawal agreement and drawing up the broad outlines of a future relationship.
The UK triggered Article 50 on 29 March 2017. So, unless something changes, the UK will leave the EU on 29 March 2019 - in exactly two months' time.
That's why you keep hearing people talk about the clock ticking.
The default position in law at the moment is that - deal or no deal - 29 March is when Brexit will happen, whether the UK is ready or not.
That could be changed by withdrawing or revoking Article 50 altogether. The UK can do that without consulting anyone else. It would mean Brexit would not happen and the UK would remain in the EU.
The other alternative is to extend the Article 50 period, allowing more time to finalise a deal, or perhaps come up with an alternative outcome via an election or another referendum.
But extending Article 50 isn't something the UK can do alone, even if Parliament were to vote in favour and force the government to act.
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The UK would need to go to Brussels to get the unanimous agreement of all 27 other EU countries and they would want to know why the request was being made.
If it was just to allow time for even more argument, they might not be impressed.
So, the UK would need to have a pretty clear plan.
If a short extension were needed for a few weeks to make sure any last-minute deal gets turned into law in the right way, that would almost certainly get the green light.
Otherwise, the EU could get the blame for a no-deal Brexit.
Even a three-month extension, until the end of June, shouldn't be too complicated. There are European elections in May but the new parliament doesn't sit for the first time until the first week of July.
That means the outgoing parliament, including UK MEPs, could be asked to sit in special session if it were needed to ratify a Brexit deal.
There is nothing in Article 50 itself that says a member state can't ask for more than one extension but any attempt to have a series of extensions could be subject to legal challenge at the European Court of Justice and would raise awkward political issues.
In fact, any extension for longer than three months, while possible in theory, gets into much more tricky legal and political territory.
It would raise a number of questions:
- Could the UK still be a full member state but have no MEPs in the European Parliament?
- Would that provoke cries of: "No taxation without representation"?
- Would the EU be willing to reopen time-consuming negotiations that it has already spent 18 months on?
- Is an extension really just another way of trying to prevent Brexit from happening by buying time for another referendum?
This is - once again - uncharted territory.
But all the arguments surrounding the idea of extending Article 50 are being discussed more and more openly as the clock ticks toward 29 March.