Just three days after a shocking vote to leave the European Union, millions of Britons are asking for a do-over. But is it possible to stop the process?
Technically, yes. While the chances are slim, there are several ways the UK could reverse course.
1) Members of Parliament vote against it
The referendum vote to leave the EU is not binding––the decision must be officially ratified by Parliament, following any legal challenges.
This gives the Members of Parliament, who mostly oppose the Brexit, an opportunity to vote to stay in the EU. However, the people have spoken, and the MPs have a responsibility to represent their interests.
"Opposing the will of the people is not going to help you get elected next time, particularly if you are in a marginal constituency," write James Knightley, Chris Turner and Carsten Brzeski of ING Group.
2) A re-do referendum
Over 3 million UK residents signed a petition on Parliament's site demanding a second vote take place, the largest petition the government's website has ever seen. Parliament must debate any proposal with over 100,000 signatures.
The petition, which launched before the referendum, asked for a second vote on EU membership if support for the remain or leave vote was below 60% with turnout under 75%.
Thursday's British exit vote had only 52% backing on a 72% turnout. While the petition must be considered by Parliament, members do not need to act on it.
3) EU concessions
Before Britain invokes Article 50 of the Treaty on European Union, the never-used provision that sets out how a country would leave the union, the EU could negotiate more favorable terms with the UK.
"The EU offered major concessions after Danish voters initially rejected the Maastricht Treaty and Irish voters opposed both the Nice and Lisbon Treaties. It is therefore possible that some members want to keep the EU together at all costs and are prepared to offer the UK more on migration," write Knightley, Turner and Brzeski.
However, given that the free movement of people is one of the EU’s central tenets, many EU members will likely oppose further negotiations on this front, add Knightley, Turner and Brzeski. "Getting an agreement to give the UK more power to control EU migration whilst staying in the EU does not appear to be a probable outcome," they write.
4) Scotland and Northern Ireland veto the decision
Per the Scotland Act 1998, the Scottish Parliament would need to approve measures that remove EU law from Scotland, according to the House of Lords report "The Process of withdrawing from the European Union."
The report states that same might be true for Northern Ireland. However, this is simply an interpretation and not the letter of the law. Also, the UK Parliament ratified the Scotland Act, and it's possible they could override a potential veto by amending the Act.
"What we do know is that the longer it takes to decide the outcome, the greater the political and economic costs for both the UK and the EU," write Knightley, Turner and Brzeski.
Given that Prime Minister David Cameron has already announced his resignation and many EU members are calling for a quick separation, the path toward a Brexit will likely be difficult to stop.
“It’s not an amicable divorce, but it never really was a close love affair anyway,” said Jean-Claude Juncker, EU Commission President.
Follow Justine on Twitter @jj_under