Here’s what has to happen before Britain can leave the EU

Britain’s vote to leave the European Union last week has left many people wondering how exactly that exit will take place. No nation has left the EU before, and in order for Britain to do so, it must first sort through decades of legislation between itself and the other 27 member states, covering everything from the products U.K. citizens use to how they travel.

Although the unprecedented nature of “Brexit” makes the process uncertain, here are the basic steps Britain must take before it’s officially out.

1. Elect a new prime minister

Shortly after the announcement of the “Leave” outcome, Prime Minister David Cameron, who had strongly campaigned to stay in the EU, announced that he would step down. A change in leadership is not required for Britain to exit the EU, but Cameron decided it would be in Britain’s best interest. “I do not think it would be right for me to try to be the captain that steers our country to its next destination,” he said in his resignation statement. He plans to leave office by October and let Britain’s next prime minister start the formal process of exiting the EU. Boris Johnson, London’s former mayor and a strong advocate of leaving the EU, is among the top contenders to succeed Cameron.

2. Put together a Brexit plan

Currently, there is no consensus among Brexiteers about how to approach negotiations with the EU. By staying until the fall, Cameron is allowing the Conservative Party some time to flesh out the rough-sketch plan proposed by the Leave campaign. Curbing immigration and establishing a U.K.-EU trade deal are among actions the campaign suggested.

3. Notify the European Council.

The EU exit process is outlined in Article 50 of the Treaty on European Union and begins with the departing country formally notifying leaders from each of the EU member countries through the European Council. It is unclear when Britain will do this, but it will not happen until after Cameron resigns in October.

4. Negotiate the terms of separation

Once the European Council is notified, Britain has two years to negotiate the terms of its exit. During this period, Britain will still be treated as a member of the EU and subject to all its rules and responsibilities. Negotiations will determine whether the U.K. will still have access to the EU single market, and what to do with the 3 million EU citizens living in the U.K. and the 1.2 million British citizens living in other EU countries, among a myriad of other decisions. Jan Techau, director of Carnegie Europe, a foreign-policy think tank, told CNN that the EU will probably be tough on the U.K. in negotiations to deter other countries from trying to follow Britain’s example. “It’s quite clear they will have to unify around a position that will make it quite painful for the U.K. to negotiate this exit so that everybody sees what happens to you if you try to do the same thing,” Techau said.

5. Get the EU to approve the terms

The European Parliament needs to approve the terms with a simple majority vote, and the Council of the European Union needs to approve it with a qualified majority of 20 out of the 27 remaining EU members.

6. Get the British Parliament to approve the terms

Although not technically required by British law or Article 50, Britain’s political climate demands the negotiated terms of separation be brought before the nation’s Parliament before it can be ratified.

7. Do it all in 2 years.

From the time that Britain notifies the European Council of its plans to leave, it has two years to complete negotiations. When that deadline comes, Britain will lose its membership automatically, whether or not it has made arrangements for trade and other transactions with other European countries. The deadline can be extended, however, with unanimous agreement from the European Council.

8. Or … hold another referendum

Some British officials, including Health Secretary Jeremy Hunt, have suggested there should be a second referendum to let people accept or reject the terms of the EU exit deal. Hunt told the BBC that the terms of negotiated trade deals are a “huge decision” and that citizens should be able to voice their opinions. There is nothing legally preventing another vote if public pressure mounts for such a referendum.