1. We don’t immediately leave the EU. This is an advisory vote to the government, who choice choose to ignore it, but won’t.

2. David Cameron will likely announce his resignation quickly, but will stay in post until his successor is knows. Paragraph 2.10 of the Cabinet Manual says he has to advise the Queen on who should form the new government before he can go. So the Conservative Parliamentary party will whittle the field down to two candidates and the party membership will then vote by post. This could take two to three months and most probably result in having to wait until the Conservative Party Conference in September

3. We have to have a period of negotiations about our future relationship with the EU, as set out by Article 50 of the Lisbon Treaty. Article 50 gives us a two year window for negotiating withdrawal terms, which can only be extended if about 20 of the remaining 27 member states (a ‘qualified majority’) allow it to be. If they don’t allow an extension, and we don’t have a deal after two years, we leave automatically on terms we may not like

4. So Article 50 skews the balance of power in negotiations in favour of the Member states. We revert to WTO rules on trade, with the tariffs that encompasses, if we can’t get a deal in two years. Some countries would strike a hard bargain so we won’t get our way on everything.

5. Article 50 doesn’t have to be triggered now. It would be sensible to work out a negotiating position first and hold preliminary discussions with other member states. But there shouldn’t be too much of a delay as uncertainty can be damaging too.

6. There is no other option than Article 50 for UK withdrawal – Article 48 sets out the procedure for revising EU treaties, but even a request for this to even be considered can be blocked for by a simple majority of member states. Given they know how much Article 50 skews the balance of power in their favour – they will insist on its use.

7. The whole process would take several years, during which the UK will remain in the EU – The Vote Leave campaign it would like the Article 50 process to be completed by 2020. Until that negotiation process is complete, the UK remains fully subject to its obligations under EU law. So the measures that Vote Leave have talked about in the event of a vote to leave, including VAT changes or limiting the write of the European Court of Justice – would violate the law.

8. There are three sets of negotiations involved in the process of withdrawal – we need to negotiate withdrawal terms – such as the rights of UK citizens living in member states and EU citizens living here. We need to negotiate a trade deal with the EU, which Vote Leave argues is in member states’ interests as we import more from the EU than we export to them. This might be so in goods, but it isn’t so in services, and the access of our financial services industry to the EU could be limited. We then have to negotiate terms of individual membership of the World Trade Organisation (WTO) and trade deals with over 50 countries that currently have deals with the EU. The WTO has already said the UK probably won’t have the same deal that the EU has.

9. Parliament has no formal say over whether or when Article 50 is invoked – the government has royal prerogative powers to do this itself. Parliament DOES however have veto rights in respect of treaties. Should Parliament pass a motion calling on the Prime Minister not to invoke Article 50, the PM could claim the popular vote justifies ignoring them.

10. Parliament CAN vote on the withdrawal deal – as that is a treaty – Parliament would need to be updated regularly on the negotiations and have its views heard. It could thus reject any trade deal that it doesn’t like. Whether it would do so depends on the political situation and the state of public opinion at the time. Also, if the two year Article 50 window were near to closing, rejecting any deal on the table would be very risky.

11. Parliament will also have a great deal of legislating to do – The European Communities Act (ECA) 1972, needs to be repealed. Legislation passed to enact provisions required under EU membership could be reviewed, amended and perhaps repealed. On the other hand, some EU regulations (remember, legislation and regulations are different things) that are important would need to be retained through Parliament or we would lack rules on some important matters. Much of the trading done in the City of London would become illegal unless this was done.This whole process will be lengthy, complex and contested.

12. Whitehall would be severely stretched by the mammoth exercise of withdrawal – After the cuts of the past six years (20% of total employment) the civil service  has no spare capacity. The UK has no current capacity at all in trade negotiations as this has been outsourced to Brussels for the past 40 years. Reviewing 40 years of EU and domestic legislation could take five or ten years. Whitehall would be extremely distracted so any new policies the Government wants to implement will get very bogged down.

13. Scotland and may make moves for independence soon – as expected, Scotland voted to Remain by a long way. Nicola Sturgeon will be watching the polls, and the oil price, very closely. But let’s not forget that a combination of Brexit AND Scottish independence would create an EU border between Scotland and England, which would surely make Scottish independence harder.

14. The sense of nationalist grievance could be further aroused by the withdrawal process itself – The Scottish Parliament, Welsh Assembly and Northern Irish Assembly are all legally required to operate within EU law. These requirements would have to be repealed to withdraw from the EU cleanly BUT this would by convention required the consent of the devolved legislatures – which they COULD refuse to grant. Should Westminster choose then to override such a refusal, we could have a constitutional crisis.

15. Brexit could undermine the Northern Ireland peace process. The EU has given significant funding to peace initiatives in Northern Ireland, which, like Scotland, voted to Remain. There may also need to be the imposition of a ‘hard border’ between the Republic of Ireland and Northern Ireland as the existing Common Travel Area between the two may not be able to be maintained. The past 20 years has removed the border as an issue in Northern Irish politics and helped the stability and cohesion of power sharing arrangements. No more.

16. There is no easy route to a second referendum – There has been much talk of whether we could have a second referendum to finalise our future relationship with the EU. Boris Johnson floated the idea last year of a Brexit vote not actually meaning Brexit, but an opportunity to negotiate radically revised terms of ongoing membership. This would be politically very difficult for any Prime Minister to pursue. A second referendum could be to accept the terms of any deal negotiated OR stay in the EU after all. This is legally perilous as Article 50 provides no mechanism for withdrawing the notification to leave the EU and the two -year limit means that if we rejected a deal we could find ourselves on the outside by default. So we should presume that leave means leave.

The information in here has been provided by Dr Alan Renwick of the Constitution Unit at UCL in this article